Journal of Crystal Growth, Vol.301, 993-996, 2007
III-V dilute nitride-based multi-quantum well solar cell
Photovoltaic properties of a preliminary set of 1-1.2 eV dilute nitride GaAsN/GaAs MQW solar cells grown by chemical beam epitaxy are investigated. The study reveals, as expected from the enhancement of effective masses, unusually high photo-conversion strength of the MQW region that exceeds by nearly two-fold those reported for conventional MQW solar cells of comparable bandgaps. Despite a current output (similar to 25 A m(-2) in absence of ARC) comparable to that of conventional GaInNAs solar cells, output voltages (e.g. similar to 0.6 V for a 1.1 eV MQW cell) appear to be significantly higher than those reported for bulk-like counterparts. Bias-dependent external quantum efficiency measurements reveal an incomplete collection of photo-generated carriers from the wells under operating conditions (forward bias), which should be mitigated by the use of thinner barrier. (c) 2007 Elsevier B.V. All rights reserved.
Keywords:chemical beam epitaxy;quantum wells;semiconducting III-V materials;dilute nitride;solar cells