Optoelectronic and morphology properties of perovskite/silicon interface layer for tandem solar cell application

Silicon (Si) solar cell has low optical absorption because of the low and indirect bandgap of Si, and the efficiency was trapped at 25% for 15 years. Si solar cell is able to achieve efficiency up to 30% by adding perovskite as multiple bandgap material through tandem formation. In this paper, the Si/perovskite interface layer was characterized to study the compatibility of perovskite on fluorine‐doped tin oxide (FTO) glass and p‐type Si wafer (p‐Si). The single solution deposition step of methyl ammonium lead iodide, CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite film, was spin‐coated at different concentration. The physical properties of the MAPbI 3 /FTO and MAPbI 3 /p‐Si were obtained by profilometer, atomic force microscope, X‐ray diffraction, and Raman spectroscopy. The optical properties were analyzed by ultraviolet‐visible spectroscopy, photoluminescence, and infrared transmission. Then the electrical properties were measured by Hall effect. From the measurement, it is observed that 1.2M concentration of MAPbI 3 thin film has the highest thickness, smoothest film surface, and largest crystallite size compared with 0.8M and 1.0M. It is found that there is an interaction in perovskite/Si interface and caused in a low‐wavelength shift, and the increase in concentration of MAPbI 3 helped in intensifying the Raman signal produced. 1.2M MAPbI 3 thin film had the highest enhancement in light trapping property rather than 0.8M and 1.0M. The bulk concentration and conductivity of 1.2M perovskite were higher, but the resistivity was lower than 0.8M MAPbI 3 because of more CH 3 NH 3 I and PbI 2 concentration within MAPbI 3 perovskite compound.