Radiation response of multi-quantum well solar cells: Electron-beam-induced current analysis

Abstract

Solar cells utilizing multi-quantum well (MQW) structures are considered promising candidate materials for space applications. An open question is how well these structures can resist the impact of particle irradiation. The aim of this work is to provide feedback about the radiation response of In0.01Ga0.99As solar cells grown on Ge with MQWs incorporated within the i-region of the device. In particular, the local electronic transport properties of the MQW i-regions of solar cells subjected to electron and proton irradiation were evaluated experimentally using the electron beam induced current (EBIC) technique. The change in carrier collection distribution across the MQW i-region was analyzed using a 2D EBIC diffusion model in conjunction with numerical modeling of the electrical field distribution. Both experimental and simulated findings show carrier removal and type conversion from n- to p-type in MQW i-region at a displacement damage dose as low as ∼6.06–9.88 × 109 MeV/g. This leads to a redistribution of the electric field and significant degradation in charge carrier collection.

Thermally propagated Al contacts on SiGe nanowires characterized by electron beam induced current in a scanning transmission electron microscope

“…[16][17][18][19] However, even in low dimensional materials such as nanowires, the generation of charge carriers in SEM is not uniform with depth and spreads laterally, degrading the spatial resolution of the technique. Careful modelling of the generation volume is required to deconvolve its shape and density distribution from the EBIC map [20][21][22] , especially in complex geometries such as nanowires, where the size of the generation volume is comparable to the specimen dimensions [23][24][25][26][27] . Scanning transmission electron microscopy (STEM) EBIC [28][29][30][31][32][33] uses a high energy beam in the range of 80 -300 kV to form a localized generation volume which is uniform through the thickness of the nanowire, greatly simplifying the interpretation of the EBIC maps.…”