Abstract: Organic-inorganic hybrid perovskite CH₃NH₃PbI₃ film is prepared on p-type silicon substrate using the one-step solution method to form a CH₃NH₃PbI₃/p-Si heterojunction. The film morphology and structure are characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The photoelectric properties of the CH₃NH₃PbI₃/p-Si heterojunction are studied by testing the current-voltage (I-V) with and without illumination and capacitance-voltage (C-V) characteristics. It turns out from the I-V curve without illumination that the CH₃NH₃PbI₃/p-Si heterojunction has a rectifier feature with the rectification ratio over 70 at the bias of ± 5 V. Also, there appears a photoelectric conversion phenomenon on this heterojunction with a short circuit current (I_{m sc}) of 0.16 μA and an open circuit voltage (V_oc) of about 10 mV. The high frequency C-V characteristic of the Ag/CH₃NH₃PbI₃/p-Si heterojunction turns out to be similar to that of the metal-insulator-semiconductor (MIS) structure, and a parallel translation of the C-V curve along the forward voltage axis is found. This parallel translation means the existence of defects at the CH₃NH₃PbI₃/p-Si interface and positive fixed charges in the CH₃NH₃PbI₃ layer. The defects at the interface of the CH₃NH₃PbI₃/p-Si heterojunction result in the dramatic decline of the V_oc. Besides, the C-V test of CH₃NH₃PbI₃ film shows a non-linear dielectric property and the dielectric value is about 4.64 as calculated.

Key words: perovskite solar cells, heterojunction, CH₃NH₃PbI₃/p-Si, I-V, C-V