Characterization of GaAs Solar cells grown by hydride vapor phase epitaxy in horizontal reactor

The use of highly efficient III-V multijunction devices is limited to space high-concentration terrestrial applications owing to their extremely high manufacturing cost. In this study, we characterized GaAs solar cells grown by hydride vapor-phase epitaxy (H-VPE) in a horizontal reactor, in order to develop a low-cost, high-throughput growth technique. Secondary ion mass spectroscopy showed that the doping transition zone during H-VPE growth was narrow at 40 nm. The characterization of the thickness distribution of 5-µm-thick GaAs films grown on 2-inch GaAs wafers showed that the distribution could be improved from 30.1% to 2.5% by modifying the gas flow pattern and by rotating the substrate. The GaAs solar cell grown with a In GaP window layer without using an antireflection coating exhibited short-circuit current density, open-circuit voltage, fill factor, and efficiency values of 16.2 mA/cm2, 0.91 V, 85.93%, and 12.67%, respectively.