The CDT Programme

Supervised by Professor Molly Stevens (Materials, Imperial College) and Professor Martin Heeney (Chemistry, Imperial College)

This project has been filled and is no longer available.

Cardiovascular diseases are the number one cause of death worldwide. There are few therapeutic options available following myocardial infarct as cardiac tissues possess relatively low reparative and regenerative capabilities, imposing a global socioeconomic burden. Biomaterial-based strategies are being sought in the search for a much needed, innovative and timely solution. Polymer-based electroactive biomaterials have been traditionally hindered in cardiac applications because of issues concerning their biocompatibility, ability to withstand the strenuous and dynamic environment of cardiac tissues, and incapability of influencing cardiac cells following infarct.

Within this Plastic Electronics CDT studentship led by Profs Molly Stevens and Martin Heeney, we will use powerful in-house designed synthetic approaches to end-functionalised, homogenous, and electroactive conjugated oligomers, to form electroresponsive cardiac scaffolds. These materials will be formulated into the first electroactive auxetic patch capable of withstanding the native physiological cardiac environment. The unique patterning of the patch enables extension in both directions under strain to match the motion of the heart. It is envisaged that this work will have a major impact on clinical interventions towards the treatment of cardiac disease.

supervised by Dr Christian Nielsen (QMUL), Dr Matteo Palma (QMUL) and Dr Sahika Inal (KAUST)

This project has been filled and is no longer available.

Organic bioelectronics focuses on the interaction between electroactive materials and biological systems, addressing a variety of stimulation and sensing applications such as in-vivo drug delivery and neural interfacing. The organic electrochemical transistor (OECT) is a particularly useful device configuration for bioelectronic sensing. OECTs can effectively transduce ionic signals into electronic signals, although no selectivity towards specific biomarkers is present in a conventional setup. Currently, any additional functionality or selectivity is incorporated by a device engineering approach, for example through incorporation of ion-selective membranes or by modifying a device electrode with specific enzymes and consequently relying on the sensing of the enzymatic hydrogen peroxide production.

This project aims to create new specifically tailored electroactive materials with lock-and-key type functionalities built in to the three-dimensional structure to construct bioelectronic materials and devices with selectivity and specificity towards important biomarkers. This is a step change in both bioelectronic materials and device development in that we are proposing to design and synthesise completely new polymeric architectures and subsequently use them to fabricate highly selective bioelectronic devices without relying on additional modifications such as enzyme-functionalisation or incorporation of specific membranes.

Supervised by Professor Alasdair Campbell (Physics, Imperial College) and Dr Matt Fuchter (Chemistry, Imperial College)

This project has been filled and is no longer available.

Right- and left-handed circularly polarized (CP) light involves photons in the two different spin states. CP light is the basis of long distance optical quantum telecommunication (quantum cryptography), optical quantum computing, and optical spintronics. It can also be used in the detection of chiral biomolecules, including protein folding and chiral molecular labels, and medical tomographic imaging. CP photodetectors are a novel area in organic electronics, allowing the creation of highly compact, integrated devices with advantages over their bulky inorganic counterparts.

To create such organic CP photodetectors, we propose a novel approach involving induced polymer chiroptical absorption (circular dichriosm). This is achieved by blending a (normally achiral) polymer with a chiral small molecule. It will allow the creation of high bandwidth CP photodetectors with tunable wavelength range from the UV through the visible to the NIR using pre-existing high performance polymeric semiconductors. The device performance of CP photoFETs and photodiodes will be explored, along with the optical, electronic and materials properties of the novel chiral polymer/small molecule blends. The project will involve new collaborations with the photonics and nanoplasmonic groups in Imperial Physics, and with the University of Sheffield in developing new fast CP spectroscopies.

Supervised by Dr Sandrine Heutz (Materials, Imperial College) and Professor Martin Heeney (Chemistry, Imperial College)

This project has been filled and is no longer available.

The functionality of organic semiconductor thin film devices depends in most cases to a significant way on the microstructure of the film and the orientation of the molecules. One the one hand, this poses a challenge on the field, on the other hand, the ability to combine materials with very different functional and structural properties in a single device is unique to molecular systems and presents a wealth of opportunities that have so far not been fully exploited.

The goal of this project is to investigate the microstructure of molecular blends and to find ways to obtain regimes favouring isolated molecules, superstructures and phase separated domains. The application focus is on molecular spintronics and organic solar cells, given similar material systems and characterisation techniques, but different microstructural requirements. The PhD student will be able to employ a range of unique in-situ and ex-situ characterisation techniques to determine the microstructure during thin film growth and post-deposition to correlate microstructure with device properties.

Given the close connection of microstructure and device performance for many organic electronics devices, we see many synergies with other PE-CDT research projects and areas of research in organic electronics, as well as high relevance for industry partners.

Supervised by Dr Joe Briscoe (Engineering & Materials Science, QMUL) and Professor James Durrant (Chemistry, Imperial College)

This project has been filled and is no longer available.

This project proposes to produce and study photovoltaic devices which incorporate ferroelectric nanostructures in order to enhance carrier separation and device efficiency. Ferroelectric materials possess an internal electrical polarization which leads to electric fields within the material, which can extend into coupled materials up to ~100 nm from the surface of the ferroelectric. This has previously been shown to lead to enhanced photocatalytic activity and photovoltaic performance. However, in the
case of photovoltaics, the addition of ferroelectric layers is detrimental due to their insulating nature, and may not be able to influence the full device thickness.

To address this, this project will develop nanostructured ferroelectric films that will be incorporated into photovoltaic devices. The nanostructuring of the ferroelectric will allow it to be combined intimately with the photovoltaic, enhancing interactions, and also will allow carrier transport to bypass the ferroelectric, removing the insulating barrier. Device fabrication and testing will be supplemented by transient spectroscopy to develop understanding of the impact of the ferroelectric component on carrier dynamics. This understanding will then be used to design optimized device structures with the overall aim of producing devices with enhanced efficiency to demonstrate an effective new strategy toward highefficiency photovoltaics.

Supervised by Professor Laura Herz (Physics, Oxford University) and Professor Michael Johnston (Physics, Oxford University)

This project has been filled and is no longer available.

Hybrid metal halide perovskites are promising semiconductors for next-generation solar cells now achieving power conversion efficiencies in excess of 22%. However, perovskite cells currently still suffer from sub-bandgap trap states that can act as non-radiative recombination centres, reducing device efficiencies.

While the presence of traps in these materials has been inferred from charge-carrier recombination kinetics, their causes and nature are still largely unknown. Computational simulations have predicted the energies of specific point defects, however, matching experimental evidence for specific trap depths is more elusive.

This project will address this issue by implementing a new spectroscopic technique, optical-pump-THz-probe-IR-push transient photoconductivity spectroscopy, to monitor de-trapping processes that are stimulated by a short laser pulse whose photon energy is matched to the trap depth. Standard optical-pump-THz-probe techniques already in operation will be extended by a third pulse of tunable photon energy that is used to “push” charges from trap states back into the conduction or valence bands.

We will build on the resulting trap identification to develop processing protocols to remove specific hurdles to the adoption of perovskite as photovoltaic light-harvesters. We will target lead-free tin perovskites that currently exhibit dominant defect-related charge recombination, and mixed-halide perovskites for silicon tandems that suffer from trap-mediated halide segregation under illumination.

Supervised by Dr João T. Cabral (ChemEng, Imperial College) and Professor Paul Stavrinou (EngSci, Oxford University)

This project has been filled and is no longer available.

Nano-structured surfaces exhibit unique optical, physical, mechanical and electronic properties. While conventional lithography-based nanofabrication techniques, are generally low throughput and costly for large area patterning, bottom-up methods, including self-assembly and surface instabilities of soft materials offer attractive routes in terms of performance and switchability. Amongst these, mechanically-induced wrinkling provides a versatile platform for highly-ordered structures formed upon compression of laminates due to the mismatch between the mechanical properties of a thin film and its compliant substrate. Multiaxial strain fields readily yield topographical patterns down to a few nm is size, with independently tunable wavelength and amplitude. These surfaces have great potential as diffractive optical elements, tunable lasers, resonators etc, and potentially for very large scale integration. The project will combine experiments and modelling to fabricate novel optically active surfaces and evaluate their potential as photonic materials, reaching sub-wavelength dimensions.

Supervised by Professor James Durrant (Chemistry, Imperial College) and Professor Ji-Seon Kim (Physics, Imperial College)

This project has been filled and is no longer available.

Organolead hallide perovskites are attracting increasing attention for low cost photovoltaic power conversion, as well as LED’s and photodetectors. Organic interlayers are proving particularly effective for selective electron and hole extraction from the photoactive layer. In addition it has recently reported that integrated perovskite/organic solar cells where one interlayer comprises a low bandgap organic donor / acceptor junction can result in enhanced long wavelength solar harvesting and enhanced device performance. However the kinetics of interfacial electron transfer at perovskite / organic semiconductor interfaces, and the energetics of such interfaces, remain poorly understood. This project will focus on the use of a range of transient techniques available in the Durrant group to study the charge carrier dynamics in such interfaces, including the use of transient photovoltage and photocurrent optoelectronic measurements and transient absorption spectroscopies. These measurements will be complimented by the use of photoelectron, and other, spectroscopies available in the Kim group to determine the energetics of these interfaces, with the aim of developing quantitative energetics / structure / function relationships for such interfaces.

This project is in collaboration with Gwangju Institute of Science and Technology.

Supervised by Dr Firat Güder (Bioengineering, Imperial College) and Dr Tolga Bozkurt (Life Sciences, Imperial College)

This project has been filled and is no longer available.

Food security is a major concern worldwide. Plant diseases caused by filamentous plant pathogens (fungi and oomycetes), bacteria, viruses, and nematodes cause hundreds of billions of pounds in annual loses and severely impact subsistence agriculture. Pattern recognition receptors in plants recognize pathogen associated molecular patterns (PAMPs) at the cell surface and initiate a cascade of signalling events leading to PAMP triggered immunity. Our understanding of the mechanisms of activation of plant immunity is quite limited although a number of chemical signals are known to play a role as part of the immune reaction. In this project, we will develop plant growth chips with printed electrochemical sensors to detect and quantify chemical signals in living plants in real-time upon activation of plant immunity. These sensors will be designed to detect defence related fluctuations in living plants that can be scaled-up to perform high-throughput screens and will substantially accelerate cloning of new immune receptors.

Supervised by Professor Ji-Seon Kim (Physics, Imperial College) and Professor George Malliaras (Department of Engineering, University of Cambridge)

This project has been filled and is no longer available.

A recent trend in neuromorphic engineering involves the use of devices based on organic electronic materials. This is largely motivated by the attractive characteristics organic devices offer in interfacing electronics with biology. Key advantages of organic-based materials include their compatibility with low cost processing on large area, mechanically-flexible substrates that can be conformal to the body as well as the tunability of their properties via blending and chemical synthesis. The aim of the proposal is to develop organic-based composites and implement neuromorphic device architectures suitable for the processing of biological signals with a view towards applications in the field of wearable electronics, health monitoring, and neural prosthesis.

This project is in collaboration with Gwangju Institute of Science and Technology.

Supervised by Dr Steffi Krause (School of Engineering and Materials Science, QMUL), Dr Oliver Fenwick (School of Engineering and Materials Science, QMUL) and Dr Christian Nielsen (School of Biological and Chemical Sciences, QMUL)

This project has been filled and is no longer available.

High-resolution mapping of chemical activity of cells on surfaces is important for the understanding of biological processes. We are aiming to develop the first flexible and biocompatible electrochemical imaging chip for in-vivo imaging of cell activity. The groundwork for this will be laid by this PhD project by developing novel organic semiconductor coatings suitable for high-resolution photocurrent imaging and measurement of cell-signaling processes such as cell impedance, cell surface charges, release of metabolites and neurotransmitters.

Supervised by Professor Milo Shaffer (Chemistry, Imperial College) and Professor John de Mello (Chemistry, Imperial College)

This project has been filled and is no longer available.

Exfoliated 2d nanomaterials offer multiple beneficial physicochemical and functional properties in a format that can be prepared as an ink and printed to form flexible electronic devices. Graphene has attracted enormous interest but lacks a straightforward band gap, meaning it can only be conveniently used as a conductive material. Other 2d materials, such as Transition Metal Dichalcogenides (TMDs), offer a well-defined band gap, suitable for transistors, photodetectors, or emitters. By preparing and combining inks based on this palette of materials, device applications can be developed. To maximise the performance, the exfoliation process must be optimised, since the TMD properties depend on the degree of exfoliation and the lateral size of the layers, as well as their inherent structure.

Thomas Swan & Co. are developing a range of functional inks based on 2d materials. This project will explore the application of these inks to thin film electronics, linking the nature of the ink, through the deposition process, to transport properties and then device performance. The project will involve detailed characterisation using a range of advanced microscopy and scattering methods to determine the nature of the ink, establish protocols for patterned film (and hybrid film) deposition, and finally design/evaluate protoype devices. By iteration with the team at the company, new optimised materials will be developed, providing a rapid route to real world application.

Supervised by Professor Henry Snaith (Physics, Oxford University), Professor Natalie Stingelin (Georgia Tech and Materials, Imperial College), Dr Martyn McLachlan (Materials, Imperial College) and Dr Laura Miranda Perez (Oxford PV)

This project has been filled and is no longer available.

Perovskite solar cells have emerged as contenders to main-stream silicon PV. The first product likely to be manufactured is a perovskite-on-silicon tandem solar cell, which in laboratories already exceed 25% efficiency, and promises to deliver manufactural modules with efficiencies ultimately capable of surpassing 30%. Since the target of that first technology is highest efficiency, cost of manufacturing is not absolutely critical, and combinations of both solution and physical vapor deposition or sputter coating are perfectly acceptable. However, ultimately, the lowest cost perovskite solar module will be an all-printed thin film technology, monolithically coated on glass or plastic substrates. The main challenges to achieve are highly uniform coating via methodologies compatible with high volume manufacturing, and using solvent and ink compositions which are toxicologically scalable. Within this project, the PhD student will develop inks and the printing methodologies of ink-jet printing and slot-dye coating to deliver completely printed perovskite solar cells at the highest efficiency. Challenges will include developing benign solvents for both the perovskite and organic charge extraction layers, and the realization of multi-layer coatings for multi-junction cells. This project will be in close collaboration with Oxford PV Ltd. and make some use of their coating and module structuring capabilities.

Supervised by Professor Aron Walsh (Materials, Imperial College) and Professor James Durrant (Chemistry, Imperial College)

This project has been filled and is no longer available.

Electric polarisation of crystals can influence the generation, stability and transport of electron and hole charge carriers in photochemical processes. The polarisation may be at the surface (due to intrinsic surface dipoles or extrinsic chemical modification layers) or in the bulk (due to a non-centrosymmetric crystal structure with the presence of ordered polar domains). The benefits of lattice polarisation for electron-hole separation have recently been suggested in solar cells, including metal oxides and metal halides such as CH₃NH₃PbI₃. There have been several reports on performance enhancements for photoelectrochemical processes, but understanding of the underlying physical phenomena are limited.

In this project, we propose to use quantum-mechanical materials modelling to quantify polarization features and provides routes for atomic engineering of these and related phenomena in semiconducting materials. We have been developing a range of bespoke tools to separate surface, interface, and bulk contributions to absolute electron energies (ionisation potential and electron affinity) in solids [e.g. Nature Materials 12, 798 (2013) and Phys. Rev. B 95, 125309 (2017)], which will be applied to a range of topical inorganic systems and extended to organic and hybrid compounds.

Supervised by Dr Rylie Green (Bioengineering, Imperial College) and Professor Sian Harding (National Heart & Lung Institute, Imperial College)

This project has been filled and is no longer available.

Cardiac pacemakers consist of three main components; generator, lead and electrode. The lead is the principal cause of both early and late complications of pacing. Approximately 5% of all implanted leads require explanting due to infection, lead dislodgement or mechanical failure. Furthermore, traditional pacemakers are incompatible with magnetic resonance
imaging (MRI) techniques, generating unsafe amounts of heat inside the body.

This project will develop soft, flexible and electrically conductive polymeric materials designed to replace the metal components of pacemaker leads. Electrically conductive elastomers (ECEs) will be developed from composites of conductive polymers (CPs) and elastomeric materials. The project will focus on understanding how to combine these two classes of polymers to create a material capable of meeting the design criteria for flexible bioelectronics. Subsequent work will focus on the design of functional leads with an investigation of processing techniques that do not negatively impact on the ECE properties. Lead and electrodes will be developed in one step, as a continuation of the ECE material, to produce a robust device that carries less risk of fracture failure.

The research outcomes will contribute to the advancement of flexible bioelectronics, primarily focused on the development of stable, MRI compatible pacemaker leads but with clear relevance to a variety of implantable bionic devices.

Supervised by Dr Matthew Fuchter (Chemistry, Imperial College) and Professor James Durrant (Chemistry, Imperial College)

This project has been filled and is no longer available.

Considerable effort has been devoted to the development of solar fuels that store the energy of the sun in chemical bonds. An attractive but far less well developed alternative approach would be to harvest and store solar energy in a closed cycle system through the conformational change of molecules that can release the energy in the form of heat on demand. Such solar thermal fuel (STFs) could provide readily integrateable carbon neutral solutions for the provision of heat for a range of personal and industrial heating applications, and would complement other, larger scale, solar thermal conversion processes.

Azobenzenes are molecules that can be photoisomerised from the ground state E isomer to a metastable Z isomer, which subsequently thermally converts back to the ground state; a process with excellent cyclability. Thus, they have long thought to hold potential as STFs. However, there are significant molecular and materials issues for this class of molecules which have hindered their potential and development.

In this project, we plan to exploit a new class of photochromic azo compounds recently discovered at Imperial. Through iterative design-synthesis-characterisation cycles using these scaffolds we aim to develop a pioneering a new class of materials for a range of solid-state STF heating applications.

Supervised by Professor Martin Heeney (Chemistry, Imperial College) and Dr Martyn McLachlan (Materials, Imperial College)

This project has been filled and is no longer available.

This project will be focused on the development of low band gap non-fullerene acceptor materials for application in high-performance flexible and printed perovskite/organic integrated photovoltaic cells. To maximize the power-conversion efficiency of integrated solar cells, we will develop wide band gap perovskite and low band gap organic photovoltaic materials to achieve high open circuit voltages and to optimize complementary light absorption. Here we will specifically focus on the synthesis of low band gap acceptors.

This project is a collaboration with Gwangju Institute of Science and Technology.

Supervised by Dr Artem Bakulin (Chemistry, Imperial College) and Dr Piers Barnes (Physics, Imperial College)

This project has been filled and is no longer available.

Nowadays, infrared light (IR) improves our life through many applications, including non-invasive imaging for medical and security purposes, temperature sensing, and communication. Presently, IR sensors are expensive, so technologies that enable the rapid and cost-efficient detection of IR are needed. One way to produce inexpensive electronic devices is to print them from plastics, however the bandgap of most solution processible materials is too wide to absorb IR light. Same time, bulky IR-absorbing molecules are incompatible with low-cost printing techniques.

This project will research the concept of novel hybrid perovskite-based IR photodetectors that use a two-step process for light detection. The idea relies on our recent observation that some electrons in organic and perovskite electronic devices get ‘stuck’ and cannot move until they receive a ‘kick’ of additional energy. In our detector, visible light or electrical pulses will be used to create a population of immobile electrons in the photodiode material. Then, incident IR photons will be absorbed by intragap optical transitions which will provide additional energy for these electrons to move and generate an electrical current for photodetection.

These novel detectors may bring new functionalities to printable perovskite-based electronics and might allow the integration of cheap and effective IR-sensitive components to existing imaging and communication devices.

Supervised by Professor Milo Shaffer (Chemistry, Imperial College) and Professor John de Mello (Chemistry, Imperial College)

This project has been filled and is no longer available.

Carbon-based electrodes promise both cheap, printable, flexible, transparent conductors and high performance thin film transistors, crucial for large area plastic electronics. A new process developed at Imperial/LCN/UCL allows dissolution of single-walled nanotubes, without any damaging sonication or oxidation; thus, in principle, very long SWNTs can be dispersed. The process produces charged nanocarbons, which are truly individualised in solution (as shown by neutron scattering), due to electrostatic repulsion. In addition, the charging process can be selective for metallic SWNTs, or semi-conducting SWNTs, and can be used to remove other unwanted impurities. The use of long, metallic nanotubes should provide the required significant improvements in transparent conducting network performance, particularly relevant to flexible electronics. The charge can be neutralised without damage, or exploited to control the deposition process, including creating hybrid composite films, integrating other active device components. The remaining semi-conducting SWNT fractions are of interest for thin film transistors and other PE applications; the LCN approach offers prospects of separating the semi-conducting species by band gap / type.

Our SWNT separation/dispersion technology is already patented and licensed for commercialisation; the extension to further SWNT applications is very timely. Recent important developments in the field, include a two order of magnitude reduction in the price of raw SWNTs, the commercial availability of pure semiconducting SWNTs, and Fujitsu’s recent announcement of a SWNT based memory chip.

The project combines various aspects including an understanding of the physical chemistry of colloidal systems to optimize these unusual inks, materials processing and characterization of thin films, and an appreciate of device physics. The student could have a background in physical/materials chemistry or physics. The emphasis of the project would likely be adjusted to build upon the strengths of the successful candidate.

Supervised by Professor John de Mello (Chemistry, Imperial College) and Professor Iain McCulloch (Chemistry, Imperial College)

This project has been filled and is no longer available.

This project seeks to address a key weakness in the field of organic photovoltaics, namely the absence of quality controlled production methods for organic semiconductors. Using fully integrated flow-based synthesis procedures, the project aims to provide a controlled method for the production of high performance non-fullerene acceptors that can be applied to both materials discovery and large-scale (> 100 g/day) manufacturing.

It is essential that the student has demonstrably strong synthetic chemistry skills (through a final year undergraduate project), along with a keen interest in learning flow chemistry. It is desirable, though not essential, for the student to have experience in electronics and software development. This is an industrially focused project, and therefore requires an interest in process scale-up and commercial aspects of chemistry, along with excellent presentation and communication skills.

Supervised by Dr Martyn McLachlan (Materials, Imperial College), Professor Martin Heeney (Chemistry, Imperial College) and Professor Myung-Han Yoon (GIST)

This project has been filled and is no longer available.

The project described builds on existing work within the research group that has formed part if the ICL-GIST GRL. Specifically we propose an approach that focuses on compositional and morphological control of the perovskite active layer material, and importantly, interfacing this with existing and novel charge selective interlayers. We propose detailed structural and compositional characterization (primarily by using analytical tools including TEM, XPS and SIMS) thus exposing the CDT student to state-of-the-art techniques in emerging device platforms.

The development of organic and hybrid interlayer materials, in collaboration with the team at GIST, will allow a focus on tuning electronic properties of the interlayers and to allow some control over reduced degradation in devices. Preliminary results show that simple surface modifications using SAMs/small molecules can have a profound impact on device stability. Additionally using simple deposition methods , controlling the orientation of inorganic interlayers (metal-oxides) can also improve lifetime and stability.

Importantly for the training of the PhD student, key to any successful CDT project, existing relationships will be built upon across the CDT and new collaborations with the research team at GIST will be established and strengthened.

This project is a collaboration with Gwangju Insitute of Science and Technology.

Supervised by Professor Jenny Nelson (Physics, Imperial) and Dr Andreas Kafizas (Chemistry, Imperial)

This project has been filled and is no longer available.

Development of efficient solar energy conversion technologies for energy generation and storage is critical to future low carbon energy supplies. While solar-to-electric (photovoltaic) energy conversion is widely used, the storage of solar energy in the form of fuels is much less advanced. Photocatalytic fuel generation involves using a light-absorbing material to generate charges that can drive chemical reactions to generate a fuel, such as water photolysis into hydrogen and oxygen. Molecular semiconductors are extremely interesting for this application due to their tuneable, sharp and strong light absorption, low impact fabrication, and opportunity to control surface area. 

A key issue is the efficiency of the absorbed photon to charge transfer process. Even in the best functioning organic photocatalytic systems, the quenching of the photogenerated exciton is relatively weak. This stage can be improved through control of the dielectric environment, control of the microstructure of the catalyst, and by use of a heterojunction structure to drive the dissociation of excitons into separated charges. This project will explore the relationship between chemical structure, physical environment and photocatalytic activity of polymer based photocatalysts. Transient optical spectroscopy will be used as a tool to probe the efficiency of photoinduced charge transfer in different conditions. The project will investigate the advantages of using (a) nanostructured materials and (b) heterojunction structures, either based on organic-organic or hybrid organic – metal oxide heterojunctions, in improving photocatalytic activity. In particular we will investigate the trade off between light harvesting and generation of chemical potential when using heterojunction structures.

Supervised by Professor Ji-Seon Kim (Physics, Imperial College) and TBC

This project has been filled and is no longer available.

Organic sensor devices such as organic photodetectors (OPDs) are important optoelectronic applications using organic semiconductors as a light detecting active medium. OPDs have attracted significant interest in the last two decades due to the possibility for using them for a variety of industrial and scientific applications such as environmental monitoring, communications, remote control, surveillance, and chemical/ biological sensing, with low-cost, light-weight, high efficiency and high environmental friendliness. For OPD applications, it is critical for organic semiconductors to have efficient light harvesting (with high photocurrent and low dark current) and high spectral selectivity (from UV to NIR/IR) properties.  Although the rich variety of organic compounds with their absorption spanning from the UV to NIR offers unique possibilities for these required properties, organic semiconductors with a large photoresponse at NIR spectral ranges with efficient light harvesting and air stability are still very difficult to find.  In this project, we will develop key fundamental understanding of organic sensor materials and devices towards high-performance and high-stability NIR photodetectors.

supervised by Professor Ji-Seon Kim (Physics, Imperial) and TBC

This project has been filled and is no longer available.

Continuous increase in the device performance of organic and hybrid (including perovskites) solar cells is strongly related to better understanding of optical and electronic properties of the photoactive layer. There are still many electronic processes in organic/organic and organic/inorganic layers that are critical to device performance (e.g. charge carrier generation/recombination, trapping of electrons and holes, and ionic movement) and are not yet fully understood. This project aims to investigate these important electronic processes in terms of their energy levels and the illumination generated surface photovoltage and its transient behaviour. For this, Ambient pressure air photoemission spectroscopy and Kelvin Probe-based surface photovoltage techniques will be used.