Title :
The choice of silicon wafer for the production of low-cost rear-contact solar cells
Author :
McIntosh, Keith R. ; Cudzinovic, Michael J. ; Smith, David D. ; Mulligan, William P. ; Swanson, Richard M.
Author_Institution :
SunPower Corp., Sunnyvale, CA, USA
Abstract :
SunPower manufactures high-efficiency rear-contact solar cells. To offer these cells at a competitive price, SunPower requires a source of low-cost wafers with the necessary lifetime, thickness and resistivity to attain a cell efficiency of at least 20%. With simulation and experiment, this paper investigates how each of these parameters affects the efficiency of SunPower´s low-cost, rear-contact solar cell. It concludes that the cell efficiency approaches an optimum when the wafers have (i) a lifetime in excess o 1 ms, (ii) a thickness of 160-280 /spl mu/m, and (iii) a resistivity of 2-10 /spl Omega/cm (n-type). The requirement of the high lifetime restricts the wafer choice to FZ, PV-FZ or n-type Cz; but the wide tolerance on wafer thickness and resistivity help lower the wafer cost by maximizing the yield from a silicon ingot.
Keywords :
carrier lifetime; crystal growth from melt; electrical resistivity; elemental semiconductors; semiconductor device manufacture; semiconductor device models; silicon; solar cells; zone melting; 160 to 280 mum; 2 to 10 ohmcm; Si; SunPower; cell efficiency; lifetime; low-cost rear-contact solar cell; resistivity; silicon wafer; wafer thickness;
Conference_Titel :
Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on
Conference_Location :
Osaka, Japan
Print_ISBN :
4-9901816-0-3
