Light Emitting Field-Effect Transistors: A Route to Injection Lasing in Organic Materials

Organic semiconductors combine novel optoelectronic properties, with simple fabrication and the scope for tuning the chemical structure to give desired features, making them attractive candidates for the applications in almost every economic and industrial sector. Organic dye-lasers (optically pumped) are currently used in communication and medical applications because their colour can be easily tuned, and they are low-cost. However, the organic dyes used in these lasers cannot be electrically pumped because of the intrinsic limitations (poor charge transport and luminance quenching) of the organic materials, which remains a major challenge for the researchers to achieve better materials, processing methods and device architectures. This project addresses the research challenges in i) achieving high performance material combinations and device structures of novel light-emitting field-effect transistor (LEFET) that eliminate any inefficiencies for, ii) developing high speed optoelectronic devices and (iii) the creation of high current density and exciton densities above lasing threshold for suitable low-loss optical feedback structures. Electrically pumped solid-state organic lasers are highly attractive technology due to their potential in achieving colours at a relative ease, that are difficult to realise with inorganic lasers, and this will allow the improvement and creation of a wide range of new applications in communications, biomdecial sensors and displays.