Electronic and optoelectronic performance of nano-Vanadyl 2,3-naphthalocyanine/n-Si (organic/inorganic) solar cells: Temperature dependence

Abstract

Vanadyl 2,3-naphthalocyanine (VONc) /n-Si heterojunction was prepared by vacuum deposition of VONc compound onto n-Si single crystals. The analysis of the X-ray diffraction pattern and the scanning electron microscopy images reveal the nanostructure nature of the deposited VONc film. At low voltage, the temperature dependence of current density-voltage characteristics corroborates that the multi-tunneling mechanism is the dominant current mechanism for the dark forward bias. In the case of the higher forward bias (0.4 < V < 2 V), the conduction mechanism is a space charge limited current dominated by a single trap level. The capacitance-voltage characteristics imply that the junction has an abrupt heterojunction description and the value of built-in voltages, at room temperature, was estimated to be 0.67 eV. The values of the open-circuit voltage, the short-circuit current, fill factor and power conversion efficiency under illumination (100 mW/cm2) and at room temperatures were calculated to be 0.70 V, 11.30 mA/cm2, 0.394 and 3.12%, respectively. These results indicate that VONc/n-Si heterojunction is characterized by remarkable considerable photovoltaic properties comparing with the other organic/inorganic heterojunctions.