Fully funded PhD studentships are available!

The exciting projects on offer with Prof Ji-Seon Kim in 2017 are detailed below! Please e-mail Ji-Seon Kim for more information. 

Innovative Printed Organic Sensors (Fully funded) co-supervised with Prof Martin Heeney (Chemistry) and Dr Firat Guder (Bioengineering)
Project Number:  JSK 1
The project aims to develop innovative solution-processed (printed) organic sensors which enable to make fine discrimination of various external stimuli (gas, pressure, light, bio signal), ultimately facilitating the ubiquitous information system along with consumer electronics, bio-medical applications, smart buildings. We will employ a new cooperative stimulus-to-signal transducer (CSST) system comprising ionic liquid electrolytes as a stimulus receptor and pi-conjugated polymers as a signal deliver, to form an interpenetrating network at a molecular level critical for a fast stimulus-to-signal transducing with high sensitivity, responsibility and reliability. We will focus on materials design/synthesis, materials/device characterisation, and platform technology development. The success of this project will offer a new class of materials for printed sensor applications, as well as will provide significant intellectual merit by unveiling fundamental device operational mechanism.

This project is based on an industrial CASE studentship sponsored by CSEM Brasil (http://www.csembrasil.com.br/) and the EPSRC Plastic Electronics CDT. A student will be co-supervised by an industrial supervisor (Dr Diego Bagnis) and will have an opportunity to spend some time in CSEM Brasil during his/her PhD. 

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 Efficient and Stable Organic NIR Photodetectors co-supervised with Prof Martin Heeney (Chemistry, Imperial)

Project Number:  JSK 2

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 (>700 nm) 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 towards high-performance and high-stability NIR photodetector applications. Our particular attention will be paid to; (1) investigating optoelectronic properties of new organic photodetector materials (low-band gap conjugated polymer donors and non-fullerene acceptors), (2) controlling and characterising the thin film nanostructures formed in donor-acceptor blends and bilayers, and (3) fabricating highly efficient and stable organic NIR photodetectors by utilising various charge transport/ extraction organic and hybrid materials as an interlayer in a device.

Most equipment for device fabrication and characterisation is based at IC. The project will enable to strengthen a newly formed collaboration between Kim and Heeney Groups in organic sensor research. We have recently awarded the Samsung Global Research Outreach (GRO) programme grant to develop organic NIR photodetectors. Materials developed under the Samsung GRO program will be used to accelerate the outputs of the proposed project.

 

Fully funded PhD studentships are available!

The exciting projects on offer with Dr. Ji-Seon Kim in 2016 are detailed below! Please e-mail Ji-Seon Kim for more information. 

Printed Large Area Organic Solar Cells  (co-supervised with Dr. Diego Bagnis, CSEM Brasil)
Project Number:  JSK 1
 

Plastic (Printed or Organic) Electronics is a new technology that enables organic electronic devices to be printed onto a range of surfaces for large area, flexible and low-cost applications. In particular, organic solar cells based on large area printed blend films of organic semiconductors have attracted significant interest as a potential lightweight, low-cost renewable energy source. Low band-gap donor- acceptor polymers and modified fullerenes developed for solar cell devices have recently achieved power conversion efficiencies of over 11%. In spite of such remarkable progress, the fundamental understanding of organic semiconductor materials and devices in terms of their stability still remains as one of the most important scientific and technological challenges to overcome. This project seeks to provide key fundamental and technological insights into this issue. We aim to identify the important key parameters which detertmine the stability of organic solar cell materials and devices, and hence to develop highly efficient and stable printed organic solar cells as the next generataion renewable energy source. 

This project is based on an industrial CASE studentship sponsored by CSEM Brasil (http://www.csembrasil.com.br/) and the EPSRC Plastic Electronics CDT. A student will be co-supervised by an industrial supervisor (Dr Diego Bagnis) and will have an opportunity to spend some time in CSEM Brasil during his/her PhD. 

Summary of the table's contents

 

Morphology control and characterisation of organic and hybrid devices for thin-film electronics (co-supervised with Prof Iain D Baikie, KP Technology)

Project Number:  JSK 2
 

Plastic Electronics is a new technology that utilises the functionality and processibility of plastic materials (organic semiconductors and organic/inorganic hybrid materials) for a wide range of optical and electronic devices. The field of Plastic Electronics has developed rapidly over the last 25 years from fundamental laboratory discovery into a significant materials and manufacturing technology for a range of thin-film electronics applications including displays, lighting, transistors and solar cells. A major driving force in the development of this field has been the growing understanding of the complex, but crucial effect of nanoscale morphology on device prformance. However, controlling and characterising nanoscale morphology are challenging and, unfortunately, there are not many techniques avaialble, in particular to characterise the nanoscale domain structures and their optoelectronic properties at the same time. In this project, we will first control thin film morphology of organic and hybrid functional materials using various solution-deposition techniques to print them with controlled nanostructures for solar cell and transistor applications. Second, we will charcaterise these nanostructured morphologies by using the newly developed novel characterisation tool (APS04). To our best knowledge, APS04 is only one equipment available in the market which integrates important scanning probe methods including air photoemission spectroscopy (APS), scanning kelvin probe (SKP), surface photovoltage (SPV), and surface photovoltage spectroscopy (SPVS). Each technique is an invaluable tool on its own for measuring material properties in terms of work function (APS), surface potential (SKP), surface photovoltage (SPV) and surface photovoltage spectroscopy (SPVS). However, the combined application of these state-of-the-art scanning probe techniques provides a novel and powerful tool for the simultaneous determination of various advanced functional materials’ properties with high resolution and high sensitivity. We will develop a systematic understanding of the relationships between nanostructures and optoelectronic properties of organic hybrid functional materials and to correlate them to the performance of their devices. 

This project is based on an industrial CASE studentship sponsored by KP Technology Ltd (http://www.airphotoemission.com/index.html) A student will be co-supervised by an industrial supervisor (Prof Iain D Baikie) and will have an opportunity to spend some time in KP Technology Ltd during his/her PhD. 

 

High-Performance and High-Stability Organic Near-IR Sensors (co-supervised with Professor Martin Heeney, Imperial)

Project Number:  JSK 3
 

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 (>700 nm) 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 towards high-performance and high-stability NIR photodetector applications. Our particular attention will be paid to the three main areas of research; (1) developing new organic photodetector materials (low-band gap conjugated polymer donors and non-fullerene acceptors) with enhanced near-IR spectral selectivity, charge carrier mobility and air-stability, (2) controlling and characterising the thin film nanostructures formed in donor-acceptor blends and bilayers via solution processing, and (3) fabricating highly efficient and stable organic NIR photodetectors by utilising various charge transport/extraction organic and hybrid materials as an interlayer in a device. 

Most equipment for device fabrication and characterisation is based at IC. The project will enable to strengthen a newly formed collaboration between Kim and Heeney Groups in organic sensor research. We have recently awarded the Samsung Global Research Outreach (GRO) programme grant to develop organic sensor materials. Some of the materials developed under the Samsung GRO program will be used to accelerate the outputs of the proposed project. 

High Efficiency Solution-Processed OLEDs with Small Molecule TADF Emitters‌ (co-supervised with Professor Donal Bradley, Oxford, and Dr Paul Stavrinou, Imperial)

Project Number:  JSK 4
 

Great advances have been made in the materials development for organic light- emitting diodes (OLEDs) from conventional fluorescent to phosphorescent molecules. In OLEDs, electrically injected charge carriers (electron and hole) recombine to form singlet and triplet excitons in a ~1:3 ratio; the use of phosphorescent metal-organic complexes, and more importantly a class of metal- free organic electroluminescent molecules has exploited normally the non-radiative triplet excitons and so enhances electroluminescence efficiency. In metal-free organic electroluminescent molecules, the energy gap between the singlet and triplet excited states is minimised by clever molecular design, promoting a delayed fluorescence through thermally activated delayed fluorescence (TADF) which allows highly efficient spin-up conversion from non-radiative triplet states to radiative singlet states while maintaining high radiative decay rates. It provides great potential for the generation of inexpensive and high efficient light in OLED applications. Although highly efficient OLEDs based on TADF emitters have been demonstrated in vacuum evaporated devices (~20% external quantum efficiency), there has been little progress in OLEDs based on solution processable TADF molecules. In this project, we will develop high efficiency solution-processed OLEDs with small molecule TADF emitters, providing key fundamental understanding of various processes involved in device operation. 

For this project, we will take advantage of the availability of high quality materials supplied by existing commercial collaborators (CDT/ Sumitomo Chemicals), as well as via in-house synthesis (Prof Williams, Oxford) and external academic collaborations (Profs Youtian Tao and Wei Hunag at Nanjing Tech, China).