Design and optimization of very high power density monochromatic GaAs photovoltaic cells

This paper deals with the structure optimization of very high power density monochromatic GaAs photovoltaic cells and the theoretical prediction of their performance at irradiances ranging from 0.1 to 100 W/cm/sup 2/. A multifaceted optimum design including the front metal grid, device size and the semiconductor layer structure is presented. The variation in efficiency depending on emitter thickness, base thickness, emitter doping and base doping is also addressed. The objective of this is the configuration of a structure suitable for working up to 100 W/cm/sup 2/ without the detrimental influence of series resistance. For this, a detailed analysis of the effect of series resistance and the quantitative determination of its different components is carried out. The optimum wavelength is 830 nm at 300 K for all the analyzed light intensities, in which a 63% peak efficiency under an irradiance of 100 W/cm/sup 2/ for a p/n structure is obtained. The temperature effect on device performance in the 273-350 K range is also studied. Finally, the influence of device processing is analyzed.