PHOTOVOLTAIC ARRAY GAAS CELLS RESPONSE DRIVEN BY HIGH-POWER LASER-DIODES

Sandia National Laboratories is actively pursuing the safety of firing sets by replacing metal conducting paths with dielectric optical conductors. In this proposed application, the photovoltaic array (PVA) GaAs solar cells are illuminated by high power GaA1As laser diodes, which have been coupled to fiber optics in order to increase incident beam uniformity. Solar cells manufactured by Applied Solar Energy Corporation (ASEC) are rated at 1, 2, 10 and 16 V and those by Varian (assembled at Sandia National Laboratories) (V/SNL) are 2 V. The ASEC cell rated at 1 V is the most efficient (49%) at low incident optical power, followed by efficiency as low as 18% for the ASEC cell rated at 16 V. The narrower range of optimum resistance (1.1 -9.3 ohms) of the lower voltage cells causes small tolerance for matching the cells to external loads with the tolerance becoming smaller with increasing input optical power. For applications requiring high voltage (kilovolts) with large input optical power, the V/SNL solar cell rated at 2V is the best choice, since it generates the most power (0.7 W), is the most efficient (46%) and has large optimum cell resistance (5.9 ohms). The proper optical filling of the cell, uniform illumination of series connected cells and using matched segments in series connected cells are critical. © 1990.