Efficiency Enhancement of Low-Cost Heterojunction Solar Cell by the Incorporation of Highly Conducting rGO Into ZnO Nanostructure

Main issues of large-scale and large-area production of the solar cell are the high cost of fabrication due to the involvement of costly and sophisticated equipment and the use of costly materials in fabrication. Here, an effective and low-cost approach has been proposed for the fabrication of reduced graphene oxide (rGO)-ZnO/silicon heterostructure solar cells. The hybrid composite of rGO-ZnO has been synthesized by using a low-cost chemical method and deposited on a pcSi substrate by a sol-gel process for application in heterojunction solar cells. The morphology, crystal phase, surface functional groups, and optoelectronic properties of the heterostructure have been investigated by using SEM, XRD, the Fourier transform infrared (FTIR) spectroscopy, the Raman spectroscopy, and the UV-vis spectroscopy. The I- V characteristics of the fabricated heterojunction cell show a power conversion efficiency of 4.35% ( Voc= 0.51 V, Jsc= 14.47 mA ·cm-2, and fill factor (FF) = 51.60) due to having enhanced conductivity/charge transfer efficiency by the hybrid semiconductor. This simple approach assures the low-cost mass production of heterojunction solar cells.