Niel analysis of radiation degradation parameters derived from quantum efficiency of triple-junction space solar cell

Abstract

Degradation modeling of InGaP/GaAs/Ge triple-junction (3J) solar cells due to proton/electron irradiation is performed with the use of a one-dimensional optical device simulator; PC1D. By fitting external quantum efficiencies of the 3J solar cells degraded by proton/electron irradiation, the short-circuit currents (I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</inf> ) and open-circuit voltages (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</inf> ) are simulated. The validity of this model is confirmed by comparing the results of both I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</inf> and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OC</inf> to the experimental data. Then, the degradation level in each sub-cell is evaluated. The carrier removal rate of base layer (R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> ) and the damage coefficient of minority carrier diffusion length (K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf> ) in each sub-cell are also estimated. In addition, NIEL (Non-Ionizing Energy Loss) analysis for both radiation degradation parameters R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> and K <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf> is discussed.