Space degradation of triple junction solar cells at low temperatures: II ‐electron irradiation

Abstract

We investigated the behavior of electron-irradiated 3G28 InGaP/GaAs/Ge triple junction solar cells and their component (top, middle and bottom) cells at low temperatures from 100 to 300 K and low illumination intensity. Significant degradation of their performances has been observed. We found that it is induced by an excess current associated with tunneling due to the presence of the radiation-induced defects introduced in the junctions of each sub-cell. The amount of tunneling current, hence of the effect of degradation, is significantly higher in the bottom sub-cell than in the top and middle sub-cells. This particular cell is formed by diffusion of group V atoms into p-Ge substrate, which leads to relatively inhomogeneous doping profile and thus tunneling current distribution compared to well controlled top and middle sub-cells deposited by epitaxy. The degradation associated with tunneling recovers significantly at 300 K in the bottom cell.

Evaluation of electricity generation on GeSn single‐junction solar cell

“…To confine the misfit dislocation and minimize the strain, the previous study reported 6 that multijunction (MJ) III‐V devices use compositionally graded buffers, which have demonstrated solar‐to‐electrical conversion efficiency of 39.2% (1 sun AM1.5G). The Ge‐based III‐V TJ solar cells of the various bandgap combination (ie, to absorb various color band ranges of the solar spectrum) display high efficiencies 7‐9 . A number of Ge‐based III‐V TJ solar cell concepts 8,10,11 are studied by research groups around the world in order to improve the conversion efficiency and reduce devices cost.…”

“…The Ge-based III-V TJ solar cells of the various bandgap combination (ie, to absorb various color band ranges of the solar spectrum) display high efficiencies. [7][8][9] A number of Ge-based III-V TJ solar cell concepts 8,10,11 are studied by research groups around the world in order to improve the conversion efficiency and reduce devices cost. But, until now, it cannot be widely adopted in the field of civilian application due to its toxicity, poor mechanical properties, the limited abundance of III-V elements in earth, and so on.…”

Investigation of degradation characteristics of electron irradiated GaInP/InGaAs/Ge solar cell by numerical simulation model

“…3 Nowadays, the new generation solar cells for space applications are facing increasingly severe radiation environments during interstellar missions and deep space exploration. 3,4 Therefore, understanding solar cell degradation behavior under different irradiation environments is exceedingly important for precise evaluation of solar cell lifetime.…”

“…However, solar cells serving in‐orbit satellites and aircraft suffer from high‐energy radiation particles in space environment, and these particles shorten the minority carrier lifetime by generating non‐radiative recombination centers in solar cell materials, and, eventually, lead to degradation of overall cell performance 3 . Nowadays, the new generation solar cells for space applications are facing increasingly severe radiation environments during interstellar missions and deep space exploration 3,4 . Therefore, understanding solar cell degradation behavior under different irradiation environments is exceedingly important for precise evaluation of solar cell lifetime.…”