CH3NH3 Formed by Electron Injection at Heterojunction Inducing Peculiar Properties of CH3NH3PbI3 Material

The effect of formed CHNHat the heterojunction on properties of CHNHPbImaterial is investigated based on experiment and theoretical calculation. Our calculation results show that the giant dielectric constant, anomalous hysteresis and long-lasting polarization for CHNHPbIoriginate from the formed CHNHat the heterojunction. It is found that the induced weak EPS by the reorientation of CHNHsub-group along the built-in electric field enables us to effectively increase the ordering of entire lead-halide framework. In addition, the heterojunction has an advantage of channel separation between carrier transport and electron diffusion. These properties of the heterojunction are the main origin of the high efficiency of CHNHPbIsolar cells.