Thin film solar cells, active matrix displays and displays with driver electronics require crystalline silicon thin films on inexpensive, large area and/or transparent substrates such as glass for improved performance and low manufacturing costs. To achieve this goal the difficulties are: (1) amorphous nature of glass makes it impossible to employ current growth techniques that take advantage of crystalline character of the substrate. (2) the inability of relatively inexpensive glass to withstand high processing temperatures required for growth of crystalline silicon films. To overcome these problems we propose a solid state laser crystallization technique where laser pulse causes melting and re-solidification of the near surface region however short duration of laser pulse prevents sustained heating of the underlying substrate and makes the process compatible with glass substrates. The goal of the proposed program is to understand the basic science of laser crystallization using solid state lasers with near infrared wavelengths and grow amorphous silicon films by a low temperature process on glass substrates and then crystallize them by semiconductor diode lasers for seed layer followed by thicker films by plasma enhanced chemical vapor deposition to demonstrate high efficiency solar cell devices.
The research effort is Academy-Industry collaboration under the National Science Foundation GOALI program. The university faculty and graduate students will work in close collaboration with the team of scientists and engineers at the BP Solar Corporation. The university industry collaboration will provide additional opportunity for students to work with industrial scientists and use of their additional state of the art equipment facilities. Besides improvements in solar cell technology, this project will provide education to students in thin film growth, laser processing and electronic device fabrication, which are highly desired skills and important areas of current interest. The proposed program will have a strong outreach activity such as summer experience for high school teachers to work in solar energy and laser applications area, visit to industry and a display in a local museum of improved device for public knowledge and generate interest in science and engineering.
