Temperature dependence of solar cell performance-an analysis

This paper investigates, theoretically, the temperature dependence of the performance of solar cells in the temperature range 273-523 K. The solar cell performance is determined by its parameters, viz., short circuit current density (J(sc)), open circuit voltage (V-oc), fill factor (FF) and efficiency (eta). Solar cells based on semiconductor materials such as Ge, Si, GaAs, InP, CdTe and CdS are considered here. Reverse saturation current density (J(o)) is an important diode parameter which controls the change in performance parameters with temperature. In this work, reverse saturation current density (J(o)=C.T-3.exp (-qE(g)/kT)) is determined for three cases. Cases (I) and (II) correspond to C=17.90 and 50 mA cm(-2) K-3 respectively, whereas, case (III) corresponds to C.T-3=A=1.5 x 10(8) mA cm(-2). The maximum achievable V-oc, J(sc), FF and eta of solar cells are calculated for AM1.5G and AM0 spectra and are compared with theoretical and experimental results in the literature. Highest V-oc, FF and eta are achieved for case (III). The performance of cells for case (III) gives the best agreement between the calculated and available theoretical and experimental data for solar cells based on the materials, Si, Ge, GaAs whereas, for InP, CdTe and CdS, case (I) seems to be more appropriate at 298 K. Moreover, as temperature changes, cases (I) and (II) are more suitable to describe the performance of solar cells. The rate of change of performance parameters with temperature, viz., dJ(sc)/dT, dV(oc)/dT, dFF/dT and d eta/dT are calculated and compared with the available data in the literature. In addition to theoretical results, the experimentally determined performance parameters of silicon solar cells and their rate of change with temperature are also presented. (C) 2012 Elsevier B.V. All rights reserved.