Synthesis, characterization and estimation of performance parameters of binary ZnO–SnO2/p-Si heterojunction solar cells

The present work demonstrates the successful synthesis of binary ZnO–SnO 2 nanocomposite employing a simple and efficient sol-gel method. The XRD spectra confirmed the formation of a highly crystalline domain indexed to (100) planes of ZnO and (101) and (310) planes of SnO 2 . The UV–vis spectroscopy analysis revealed high transmittance over 85 % and good optical absorption , a desirable aspect for efficiency enhancement of the cell by heightened photo-excited charge carrier generation through an increased number of incident photons being striking at the junction. The optical band gap was determined using the Taucs formula and found to be 3.51 eV. To probe the possible application of ZnO–SnO 2 in Heterojunction Solar Cells (HJSCs), we carried out a numerical simulation for the estimation of cell parameters using MATLAB. The result revealed that the work function (WF) does not have a significant effect on short circuit current density (J sc ), whereas the open-circuit voltage (V oc ), fill factor (FF) and power conversion efficiency (PCE) significantly depend on the material work function. Typically V OC increased from 0.155 V to 0.665 V, FF increased from 0.586 to 0.838 and the PCE could be enhanced from 2.55 % to 15.74 %, with an estimated WF range of 4.5 eV–4.0 eV. The effect of substrate thickness was also studied, indicating increment in parameters in the range from 25 μm to 200 μm, however, no significant effect was noticed for thickness >200 μm. The simulation provides optimization of semiconductor properties through the estimation of cell parameters such as PCE, V oc , J sc and FF for enhanced performance.