Transient response of gallium arsenide and silicon solar cells under laser pulse

Solar cells can be used as receivers in laser power beaming applications. Power beamed to a photovoltaic array could power a satellite, an orbital transfer vehicle or a lunar base. Understanding solar cell response to the pulsed output of a free-electron laser (FEL) is important for evaluation of power-beaming applications. In this work we investigate the time response of gallium arsenide and silicon solar cells to a 25 nS monochromatic pulse input. The PC-1D computer code is used to analyze the cell current during and after the pulse for various conditions. For GaAs cells, current decay was studied at 511 nm, 840 nm, and 870 nm. Most of the results have been calculated for a peak intensity of 50 W/cm/sup 2/, which corresponds to nearly 1000 suns peak concentration. Compared to gallium arsenide, silicon has longer minority carrier lifetime and weaker optical absorption, resulting in longer characteristic time constants. Si cell performance was studied at 900, 950, and 1060 nm wavelengths.