Investigation of Fast Growth GaAs-based Solar Cell on Reusable Substrate by Metalorganic Chemical Vapor Deposition

GaAs solar cells can be grown with a fast growth rate without sacrificing the device performance. This paper investigates the effect of fast growth rate with metalorganic chemical vapor deposition (MOCVD) on GaAs single-junction solar cell crystal quality and device performance. The minority carrier lifetime of the samples grown with a fast growth rate (~56 μm/hr) was investigated. The growth parameters including growth temperature, V/III, and doping densities were varied to study the lifetime degradation mechanisms in the GaAs solar cell. In addition, Bi, as a surfactant, was used during the fast growth to improve the surface roughness compared to the standard growth methods with the growth rate of ~14 μm/hr. An epitaxial lift-off process was also designed to investigate the GaAs epitaxial quality on reused substrate. The goal of this work was to achieve a high quality GaAs solar cell with a fast growth on a reused GaAs substrate.