Effect of soiling on photovoltaic modules

Mechanical integrity of solution-processed perovskite solar cells

Degradation modeling of InGaP/GaAs/Ge triple-junction (3J) space solar cells, which are exposed to charged particles (protons and electrons), is introduced using a one-dimensional optical device simulator: PC1D. The proposed method can reproduce the electrical degradation of 3J solar cells from fitting the external quantum efficiencies for subcells. In this modeling, carrier removal rate of base layer (RC) and damage coefficient of minority carrier diffusion length (KL) in each subcell are considered as radiation degradation parameters. Nonionizing energy loss (NIEL) analysis for both radiation degradation parameters is discussed. The radiation degradation of a 3J solar cell can be predicted from the results of degradation level in the each subcell estimated from correlativity between NIEL and both radiation degradation parameters.

Modeling of degradation behavior of InGaP/GaAs/Ge triple-junction space solar cell exposed to charged particles

A framework is presented for understanding carrier generation and recombination mechanisms in irradiated silicon devices. Data obtained by many workers for irradiated bulk material and devices are analyzed and summarized, and key damage-factor dependences are identified. Measurements, simulations, and analyses support the conclusion that correlation of displacement damage effects with the rate of nonionizing energy loss (NIEL) for proton, neutron, pion, and heavy-ion bombardment is due to the dominant influence of defect subclusters. At low NIEL values ( 2times10-4 MeV-cm2/g), subclusters dominate. Enhanced carrier generation and recombination produced by those small disordered regions is considered. Modeling results are presented for behavior observed in the transition region between domination by isolated defects and by clusters. The model presented in this paper simultaneously accommodates defect cluster models and NIEL scaling phenomena in the same framework

A Framework for Understanding Displacement Damage Mechanisms in Irradiated Silicon Devices

Experimental and theoretical radiation damage studies on crystalline silicon solar cells

An accurate radiation degradation model, based on measured radiation damage to devices and physical principles on radiation-induced defects in Si, has been established to improve the radiation-resistance of the Czochralski (CZ)-grown and floating-zone (FZ)-grown single-crystal Si space solar cells. We have successfully carried out the optimization of radiation-resistant Si space solar cells by taking into account the effective base carrier concentration dependence of the most important analytical parameters, damage coefficient K/sub L/, for the minority-carrier diffusion length and carrier removal rate R/sub c/ for majority-carriers. The model can be used to adequately predict the radiation degradation of the Si solar cells irradiated with a complete spectrum of electron fluence. It has been established that the radiation-resistance of the silicon solar cell is very dependent on effective carrier concentration in the high fluence range and irradiation tolerance can be improved further by varying the base carrier concentration upon irradiation.

M. Imaizumi

Papers

A detailed model to improve the radiation-resistance of Si space solar cells

Mechanism for the anomalous degradation of Si solar cells induced by high-energy proton irradiation