Impact of metal electrode work function of CH3NH3PbI3/p-Si planar heterojunction perovskite solar cells

The use of p-type silicon (p-Si) as hole transport materials (HTM) has been suggested to enhance the stability of perovskite-based solar cell (PSC). We design and simulate the CH3NH3PbI3/p-Si planar heterojunction perovskite solar cell and the power conversion efficiency exceeding 18%. In the solar cell, the metal electrode work function of perovskite solar cells is a decisive factor for built-in voltage (Vbi). The device simulation revealed that the Vbi and VOC increases when rear electrode work function (фM−rear) decreasing from −4.3 eV to −4.7 eV, the Vbi almost saturate to the plateau and the performance is optimal when фM−rear = −4.8 to −5.2 eV. However, the work function of the front electrode (фM−front) also has a significant effect on the performance of p-Si perovskite solar cell. When фM−front decreasing from −3.4 to −4.0 eV, a higher performance can be obtained and the Vbi almost saturate to the plateau. The results showed the importance of the фM matching to maintain Vbi, which is useful guideline for the design of the p-Si perovskite solar cell.