Degradation fitting of irradiated solar cells using variable threshold energy for atomic displacement

Abstract

Characteristic degradation curves for proton and electron induced degradation of triple junction (3J) and isotype Ga0.5In0.5P/GaAs/Ge solar cells were obtained. The displacement damage dose methodology in combination with a varying effective threshold energy for atomic displacement Td,eff was used to analyze 3G28 and 3G30 3J cell data. The nonionizing energy loss (NIEL) was calculated analytically, and Td,eff was explicitly introduced as a fit parameter. Using the GaAs NIEL in fitting the 3J degradation data, a Td,eff of 21 eV was determined, whereas a Td,eff of 36 eV was found using the Ga0.5In0.5P NIEL. In GaAs and Ga0.5In0.5P single junction cells, the effective threshold energies for atomic displacement of 22 and 34 eV were determined. Copyright © 2017 John Wiley & Sons, Ltd.

Evaluation of tri-junction solar cells response to electrons and protons of the JUICE specific environment

“…9 disclose P max degradation versus proton and electron fluence. From these graphs, it is clear that proton degradation is fluence-dependent following a Log-dependence law as reported in [6] and [7].…”

“…V oc RF is presented here as a function of displacement damage dose in middle cell (GaAs) with 1MeV electron and proton NIELs calculated for threshold energy E d =21eV [7] (NIEL(e-) = 1.125 10 -5 MeV.cm²/g, NIEL(p+) = 0.0497 MeV.cm²/g). The "fit" curves (blue and green) for both electron and proton data are calculated with following equation: 1…”

Ab initio electronic stopping power for protons in Ga 0.5 In 0.5 P/GaAs/Ge triple-junction solar cells for space applications

“…Thus, the calculated damage is that produced by the projectile itself, the primary knock-on atoms (PKAs), and consequently generated secondary (SKAs), and not by eventual 'secondary particles' produced in nuclear reactions. The energies chosen for the impacting protons are representative of the low energy ranges used by recent studies (3 MeV [55], 1 MeV [65][66][67], 0.3 MeV [68] and 0.1 MeV [69]). It is important to note that, for such impacting energies, the particles will stop inside the solar cell, in the Ge layer (figure 5a,b), in the GaAs layer (figure 5c), or between the two active layers Ga 0.5 In 0.5 P/GaAs (figure 5d).…”

Voltage‐dependent photocurrent in irradiated GaAs solar cells

“…The D d is calculated by multiplying the particle fluences with the nonionizing energy loss (NIEL) of protons and electrons of the respective energies. In calculating the NIEL, a threshold energy for atomic displacement of 21eV was used …”