Grant: Discovery Grants Program - Individual

Since the dawn of the electronics era, progress in electronics has primarily been achieved through a reduction in device dimensions. There is, however, a certain class of electronic device that requires size in order to be useful. Displays, scanners, solar cells, and x-ray image detectors are all examples of large area electronic devices. While in conventional electronics the emphasis may be presently on sub-micron device features, in large area electronics the focus instead is on electronic devices fabricated over substrates with dimensions of the order of a square meter. As crystalline silicon cannot be uniformly and inexpensively deposited over large areas, alternate electronic materials must be employed instead for large area electronic device applications. Amorphous and polycrystalline (disordered) semiconductors, such as hydrogenated amorphous silicon, have emerged as the active electronic materials of choice for many such applications. The proposed research aims to study some of the fundamental materials issues related to this class of semiconductors. In particular, we aim to develop a series of quantitative relationships between the distributions of electronic states and the various optical properties associated with disordered semiconductors. We will then use these relationships for the interpretation of optical response data corresponding to a broad range of disordered semiconductors of interest. The transport processes that occur within these materials will also be explored. We will then use the insights gleaned from these studies in order to explore the resultant device implications. In particular, the photoconductive response of a variety of x-ray photoconductors (disordered semiconductors) will be modeled and the sensitivity and resolution of proposed digital flat panel x-ray image detectors, using these materials, will be examined. The modeling of solar cells will also be pursued. This research will help nurture the growth and development of the large area electronics industry here in Canada, an industry that has been estimated by some to have the potential to reach $ 100 Billion in sales worldwide by the year 2010.