Cost reduction technology for high-efficiency photovoltaics: Research issues and progress

An overview is presented of the Department of Energy (DOE) photovoltaic program´s research on III-V solar cells directed toward establishing the base of technology necessary to design lower cost production processes and improve the reliability of manufacturing projections. It is shown that cost reduction in the high-efficiency technologies requires a three-pronged attack. First, increasing the efficiency is still the most direct path to lowering the cost of photovoltaic (PV) modules, provided that the additional device sophistication does not add cost. The second prong is to improve the technologies for crystal growth. Production cost factors related to large-area uniformity, yield, process safety, and source utilization efficiency are inseparable from the more esoteric scientific issues such as thermal geometry, reaction chemistry, crystallographic orientation effects, spinodal decomposition, and interdiffusion. Finally, an improved technology and new concepts are needed to eliminate the cost of consuming a crystalline substrate