Organic radiation detectors

Organic materials are currently poised to revolutionise a wide range of technologies, covering applications which include carbon-based electronics, polymer-based displays, biological and chemical sensors, and smart materials. Such materials, including conjugated polymer and carbon nanotube (CNT) nanocomposites, potentially offer a range of unique properties that challenge conventional semiconductor based devices and technologies. Organic materials also potentially offer significant advantages for use as radiation detectors, although very little work has been done in this area to date. Some of the key advantages of organic radiation detectors include; a low-cost large-area detector technology, good radiation hardness, and the ability to fabricate organic detectors in unconventional geometries such as flexible sheets. There has been very little work done to date to develop organic radiation detectors to date - with the exception of a 18 month pilot study carried out by the applicants to demonstrate the feasibility of organic detector devices. This project produced two key results from test detectors fabricated from conjugated semiconducting polymer; (1) the successful fabrication of 'thick' (eg. up to 20 um) Schottky diodes with good rectifying electrical properties, (2) the high sensitivity of these devices to X-ray irradiation. These devices did not operate in photon counting mode, which was due primarily to limitations in the charge transport performance of the polymer layers. The work resulted in an international patent filing and publication in Applied Physics Letters. In this proposal we will carry out a targeted 12 month study to study a range of polymer materials specifically in terms of their charge transport properties and their sensitivity to radiation. The principle aim is to identify, from the latest generation of polymers, the best candidate materials for detector device fabrication. It is then anticipated to apply for a full PIPSS award to carry out the commercialisation of this technology.