Advanced Organic Optoelectronic Materials and Devices

Lead Research Organisation: University of St Andrews
Department Name: Physics and Astronomy

Abstract

The importance of light cannot be overstated: it allows us to see the beauty of the world around us, and supplies the energy to our planet that supports all life. It is used in countless ways in our everyday lives - to display information on computer screens or televisions, to read and write compact discs, and to carry telephone calls and internet data along optical fibres. Optoelectronics involves the study of materials and devices using light in combination with electricity. The purpose of this application is to develop a new generation of optoelectronic materials and devices. Currently most optoelectronic materials are rigid, brittle inorganic materials. This proposal will instead focus on plastic-like organic materials which can be readily dissolved and deposited in simple ways, such as by ink jet printing, to make transistors, light-emitting diodes and lasers. Remarkable progress has been made in developing these materials for display applications with commercial products available, and flat flexible screens very close.The development of these displays has led to major improvements in materials and our understanding of them, so that there are now many new opportunities and application areas. As a senior fellow I would be freed from a heavy teaching and administration load to pursue the most exciting of these opportunities. The work I would undertake can be divided into three main areas. The first is advanced materials, and will involve the development of snowflake shaped molecules called dendrimers. These materials have been extremely successful for display applications, and now have great potential for applications in solar cells, digital cameras, lasers and optical amplifiers. The second major area of research involves the development of advanced lasers and optical amplifiers using organic materials, and exploration of using these devices to allow one light pulse to switch another. These devices could be used in communication systems and would be compatible with plastic optical fibre. The last major area I plan to explore is medical applications of the materials. In particular light is used in the treatment of a large number of diseases including skin cancer, which is the most common cancer. In collaboration with the Photobiology Unit at Ninewells Hospital in Dundee, I will explore using organic semiconductors to give a new and much more convenient way of treating skin cancer.

Publications

10 25 50

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Namdas EB (2009) Phosphorescent light-emitting transistors: harvesting triplet excitons. in Advanced materials (Deerfield Beach, Fla.)

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Samuel I (2009) How to recognize lasing in Nature Photonics

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Shaw P (2008) Exciton Diffusion Measurements in Poly(3-hexylthiophene) in Advanced Materials

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Tsiminis G (2009) A two-photon pumped polyfluorene laser in Applied Physics Letters

 
Description I made significant progress in understanding and improving organic semiconductor materials and devices. In the field of light-emitting dendrimers I worked with Prof. Burn on the very challenging problem of deep-blue phosphorescence, which is important for displays and lighting. The possibility of using dendrimers to make host-free organic LEDs was very helpful, and by tailoring the dendron structure, guided by photophysical measurements, we were able to make deep-blue phosphorescent dendrimers. Another exciting development with dendrimers was my demosntration, whilst working in Santa Barbara of the world's first phosphorescent light-emitting transistor.

The development of organic semiconductor lasers was an important aspect of the project. A major aspiration in the field has been to achieve electrical pumping of such lasers. Many researchers have approached this by injecting charges into the organic semiconductor. I pursued an alternative approach of indirect electrical pumping, and showed that a gallium nitride LED could pump a polymer laser. This opens the way to low cost tuneable visible lasers, and is an important breakthrough, which was highlighted by News and Views article in Nature. In the medical field, the most exciting result obtained was the demonstration that a wearable organic LED light source (like a sticking plaster) is effective in the treatment of many skin cancers. I started a range of energy-related research. In particular I developed a method for measuring exciton diffusion, which is a key parameter in organic solar cells.
Exploitation Route Light-emitting dendrimers are being taken forwards by licences to CDT Ltd and Arborescent 2 Ltd; skin cancer treatments are being taken forward by Ambicare Health Ltd.
Sectors Chemicals,Digital/Communication/Information Technologies (including Software),Environment,Healthcare,Security and Diplomacy

 
Description One aspect of the senior fellowship was developing wearable light sources for skin cancer treatment. These have been commercialised by Ambicare Health Ltd, and have changed how some skin cancers are treated in some hospitals and clinics. the owrk is the subject of a REF impact case study adn was featured in the "Inspirational Physics for a Modern Economy" booklet of the Institute of Physics, launched at the Houses of Parliament in July 2015.
First Year Of Impact 2012
Sector Healthcare
Impact Types Economic,Policy & public services

 
Description Tayside Health Board 
Organisation Tayside Health Board
Country United Kingdom 
Sector Public 
Start Year 2007