Influence of Temperature on the Output Parameters of a Photovoltaic Module Based on Amorphous Hydrogenated Silicon

The light load current-voltage characteristics of a solar photovoltaic module based on amorphous hydrogenated silicon have been studied at different temperatures under conditions of natural solar illumination (Р_rad = 870 ± 10 W/m²). It has been found that the temperature dependence of the photocurrent has two slopes due to a change in the generation–recombination mechanism. The increase in the value of the short-circuit current with increasing temperature of the photovoltaic module is explained by a rise in the drift lengths of minority charge carriers due to an increase in the lifetime of minority carriers. In this case, the quasi Fermi level shifts to the conduction band, and the concentration of recombination centers decreases due to recharging of defective levels (D⁰ → D^–). The decrease in the value of the open-circuit voltage with increasing temperature is explained by the exponential increase in the reverse saturation current and decrease in the band gap of the semiconductor. It has been found that the fill factor (FF) of the current–voltage characteristics decreases with increasing temperature, most likely due to a decrease in the shunt resistance (R_sh), which connects parallel to the p–n junction, consists of parasitic resistances, and leads to an increase in leakage currents. The temperature coefficient of the maximum output power has a positive value in the range of 320–332 K, i.e., increases with temperature. It has been revealed that the values of shunt and series resistance decrease with increasing temperature. A large loss of power output (up to 19%) has been observed on the series resistance of the solar photovoltaic module in the temperature range of 320–332 K. With increasing temperature, the loss of generated power on the shunt resistance grows sublinearly. The efficiency of the solar photovoltaic module decreases from 7.95 to 7.65% and has a coefficient of temperature dependence of efficiency, which decreases from \({{K}_{{{\text{Ef}}{{{\text{f}}}_{1}}}}}\) ≈ –0.046 to \({{K}_{{{\text{Ef}}{{{\text{f}}}_{2}}}}}\) ≈ –0.029%/K.