Grain enhancement of thin silicon layers using optical processing
We describe a new technique for producing large-grain, poly-Si thin films on low-cost glass substrates for solar cell applications. A layer of fine-grain poly-Si is deposited on metal-coated substrate followed by a grain enhancement using optical/thermal annealing at low temperatures (approximately 500 °C). The results show that in thin-layer silicon, less than 3 microns, grains can be formed in a short time (few minutes) with grain sizes larger than the film thickness. The possible mechanisms involved in this process are also presented.