Analysis of photovoltaic cell parameters of non-vacuum solution processed Cu(In, Ga)Se-2 thin film based solar cells

Abstract

The losses in Cu(In, Ga)Se2 (CIGS) solar cells due to photovoltaic (PV) cell parameters, namely the shunt resistance Rsh, series resistance Rs, diode ideality factor n, and reverse saturation current density J0, were analyzed in this study. The PV cell parameters of the solar cells were analytically determined for various doping concentrations of Cu and In in CIGS films. The CIGS films were deposited using a low cost non-toxic solvent (deionized) by a non-vacuum process (spray pyrolysis technique). They were subsequently characterized using XRD, FE-SEM, I-V and UV-Vis techniques to correlate the structural, electrical, and optical properties of the films with solar cell performance. Maximum short circuit current density of 0.0218A/cm2 is achieved for Cu/Se and In/Se molar ratios of 0.131 and 0.318, respectively. However, the maximum obtained Voc value is 0.431V for Cu/Se and In/Se molar ratios of 0.105 and 0.191, respectively. The maximum achieved efficiency was ~4.38% for Cu/Se and In/Se molar ratios of 0.105 and 0.191, respectively. Analytically predicted values of Rsh, Rs, n, and J0 were 116.82Ωcm2, 4.64Ωcm2, 1.8016, and 1.4952×10-6A/cm2, respectively. © 2014 Elsevier Ltd.