Temperature dependency of electronic and optoelectronic performance of 2,4-Bis[4-(N,N-dibenzylamino)-2,6-dihydroxyphenyl]squaraine/n-Si organic/inorganic heterojunction for photovoltaic application

Abstract

The potential of squaraine dyes in solar cells lies in their ability to strongly absorb in the visible and near-infrared regions, as well as their high molar absorptivity. Vacuum deposition was used to prepare a heterojunction (HJ) of 2,4-Bis[4-(N,N-dibenzylamino)-2,6 dihydroxyphenyl]squaraine dye (SQ) thermally deposited onto n-type Si wafer. The SQ film was analyzed using atomic force microscopy, which revealed an average grain size of 35 nm. X-ray diffraction procedure was applied to recognize the internal crystal structural properties of the SQ film deposited onto n-type Si wafer, showing that it has a nanostructure with a crystal size of 23 nm. The absorption study revealed that the SQ film has two band gaps, measuring 1.71 and 2.23 eV. The electronic properties of the SQ/n-Si HJ were analyzed under varying temperatures (298–378 K) in dark conditions. The current density-voltage (J-V) and capacitance-voltage (C–V) procedures were applied to extract the diode parameters of SQ/n-Si HJ, which displayed temperature-dependent behavior. The SQ/n-Si HJ exhibited photovoltage conductivity under light, allowing for the evaluation of photovoltaic parameters. At room temperature, 7.596 mA/cm2, 0.625 V, and 2.04% corresponding to photovoltaic parameters of SQ/n-Si HJ were obtained for short-circuit current (Jsc), open-circuit voltage (Voc) and power conversion efficiency (PCE%), respectively. However, it was observed that these photovoltaic parameters decreased as the temperature increased. These findings suggest that the SQ/n-Si HJ has the potential for utilization in photovoltaic devices.