Perovskite materials possess n-type and p-type electrical conductivity through a control over perovskite precursor composition and stoichiometry during the film formation. A p-n homojunction can be constituted between the p-type perovskite and the n-type perovskite and a built-in electric field is formed, which can promote the oriented transportation of the photon-generated carriers and reduce the carrier recombination losses. In this paper, the numerical simulation of p-n homojunction methylammonium lead iodide (MAPbI₃) solar cells has been performed and the effects of different electron transport layer (ETL) materials and hole transport layer (HTL) materials, defect density and thickness of the absorber layer and interface defect density on the device photovoltaic performance have been studied. Simulation results show that TiO₂ and Spiro-OMeTAD are the most promising ETL material and HTL material, respectively. To improve device performance, the defect density of the p-type MAPbI₃ absorber layer needs to be as low as 10¹⁵ cm⁻³ and an optimal absorber thickness of 0.4 μm needs to be guaranteed. Moreover, the device performance is further improved by maintaining the interface defect density less than or equal to 10⁹ cm⁻². With these optimizations, a conversion efficiency of 27.10% is achieved for the homojunction perovskite solar cells with a structure consisting of FTO/TiO₂/n-type MAPbI₃/p-type MAPbI₃/Spiro-OMeTAD/Au. Hence, the device structure with perovskite homojunction provide an effective approach towards development of highly efficient solar cells.

钙钛矿材料通过在膜形成期间控制钙钛矿前体组成和化学计量而具有n型和p型电导率。可以在p型钙钛矿和n型钙钛矿之间构成pn同质结，并形成内置电场，该电场可以促进光子产生的载流子的定向传输并减少载流子复合损失。本文对pn同质结甲基铵碘化铅（MAPbI ₃）已经进行了太阳能电池，并且研究了不同的电子传输层（ETL）材料和空穴传输层（HTL）材料，缺陷密度和吸收层厚度以及界面缺陷密度对器件光伏性能的影响。仿真结果表明，TiO ₂和Spiro-OMeTAD分别是最有前途的ETL材料和HTL材料。为了提高器件性能，p型MAPbI ₃吸收层的缺陷密度必须低至10 ¹⁵  cm ^-3，并且需要确保0.4μm的最佳吸收层厚度。此外，通过保持界面缺陷密度小于或等于10 ⁹  cm，可以进一步提高器件性能。⁻²。通过这些优化，具有由FTO / TiO ₂ / n型MAPbI ₃ / p型MAPbI ₃ / Spiro-OMeTAD / Au组成的同质结钙钛矿太阳能电池的转换效率达到27.10％。因此，具有钙钛矿同质结的器件结构为开发高效太阳能电池提供了有效的方法。