Energy loss process analysis for radiation degradation and immediate recovery of amorphous silicon alloy solar cells

Abstract

Performance degradation of a-Si/a-SiGe/a-SiGe triple-junction solar cells due to irradiation of silicon ions, electrons, and protons are investigated using an in-situ current-voltage measurement system. The performance recovery immediately after irradiation is also investigated. Significant recovery is always observed independent of radiation species and temperature. It is shown that the characteristic time, which is obtained by analyzing the short-circuit current annealing behavior, is an important parameter for practical applications in space. In addition, the radiation degradation mechanism is discussed by analyzing the energy loss process of incident particles (ionizing energy loss: IEL, and non-ionizing energy loss: NIEL) and their relative damage factors. It is determined that ionizing dose is the primarily parameter for electron degradation whereas displacement damage dose is the primarily parameter for proton degradation. This is because the ratio of NIEL to IEL in the case of electrons is small enough to be ignored the damage due to NIEL although the defect creation ratio of NIEL is much larger than that of IEL in the cases of both protons and electrons. The impact of "radiation quality effect" has to be considered to understand the degradation due to Si ion irradiation.

Low‐Energy Electron‐Induced Transformations in Organolead Halide Perovskite

“…10 11 W m −2 ). Also, at low incident energies, the ionization effect should dominate over displacements . It should be noted that the radiation‐induced degradation decreases with a decrease in the incident energy and becomes hardly measurable at about 4.5 eV, which is close to the calculated HOMO binding energy of MA + in defect‐free bulk perovskites (4.5–5 eV) …”

“…The measured decrease in I and N follows the law given in (1), as shown in Figure . Interestingly, the fitting parameter C appears close to that obtained for short‐circuit current dependence on the ionizing dose upon high‐energy electron‐induced damage of amorphous silicon alloy solar cells ( C =0.6) . Therefore, even the doses at which the properties of these materials start to markedly change (expressed by D ) are different, their relative degradation rates (expressed by C ) are comparable.…”

“…The radiation damage of solar cells has been to date investigated for high‐energy particles, typically in MeV energy region . Generally, according to extensive experimental research, radiation‐induced degradation of solar cell properties follows a logarithmic dependence and can be expressed by the following empirical formula: …”

Low‐Energy Electron‐Induced Transformations in Organolead Halide Perovskite

“…Also,a tl ow incident energies, the ionization effect should dominate over displacements. [19,22,23] It should be noted that the radiation-induced degradation decreases with adecrease in the incident energy and becomes hardly measurable at about 4.5 eV,w hich is close to the calculated HOMO binding energy of MA + in defect-free bulk perovskites (4.5-5 eV). [8] Therefore,w ep ropose that low-energy electron-induced degradation of MAPbI 3 is triggered by electron impact dissociative ionization of methylammonium ion MA + (CH 3 NH 3 + ), which results in breakage of the C À Nb ond.…”

“…Interestingly,the fitting parameter C appears close to that obtained for short-circuit current dependence on the ionizing dose upon high-energy electron-induced damage of amorphous silicon alloy solar cells (C = 0.6). [23] Therefore,even the doses at which the properties…”