No abstract

Radiation-induced defects are responsible for solar cell degradation. The effects of radiation and annealing on the defects of a GaAs/Ge solar cell are modeled and analyzed in this paper. The electrical performance and spectral response of solar cells irradiated with 150 keV proton are examined. Then, thermal annealing was carried out at 120°C. We found that the proportion of defect recovery after annealing decreases with increasing irradiation fluence. The minority carrier lifetime increases with decreasing defect concentration, which means that the electrical performance of the solar cell is improved. We calculated the defect concentration and minority carrier lifetime with numerical simulation and modeled an improved annealing kinetic equation with experimental results.

Internal charging effect and discharging effect in a dielectric material are one of the key factors threatening the spacecraft safety. Most of the spacecraft charging models could calculate only the voltage variation and electric field distribution in the spacecraft internal charging process, without estimating the consequence of discharging, such as the magnitude of voltage drop and discharging current. In this article, we present a combined model which could calculate both the charging effect and the discharging effect on polymer. The model is verified by the experimental results, and it shows that the residual voltage after discharging and the pulse width of discharging current grow with the increase of polymer resistivity. The magnitude of discharging current is determined by the breakdown electrical field.

By introducing a new term into the traditional Rose-Fowler-Vaisberg model, The exponential relationship between radiation induced conductivity and dose rate is explained. The evolution of radiation induced conductivity under different radiation conditions are also analyzed. The result indicates that dose rate mainly changes the magnitude of radiation induced conductivity while the long-time decay of radiation induced conductivity is determined by carrier recombination rate of the material.

Deep charging and discharging effect is one of the key factors threatening the satellites safety in space environment. We develop a new model and simulate the surface potential evolution, internal charge distribution and electrical field distribution in the polymer charged by electron beam of different intensities. The results are compared with experimental results, which show that the polymer′s surface potential increases with electron beam intensity and its resistance, and the time to reach charging equilibrium is determined mainly by the polymer′s resistance.