Two-dimensional modeling of TiO2 nanowire based organic–inorganic hybrid perovskite solar cells

• The TiO2 nanowire-based perovskite solar cells is simulated using a 2D model.
• The optical and electrical responses are coupled in calculation.
• The electron concentration of TiO2 nanowires has a marked impact on the performance of cells.
• An optimum thickness of 600 nm for the TiO2 nanowires array is obtained.
• The collection of carriers through TiO2 nanowire is less than 5%.

Organo-metal halide perovskite solar cells have shown unique charms in the upgrade rate of maximum power conversion efficiency, the diversity of device architecture and facilitated fabrication process. And the clear understanding of the role of each component and the basic working mechanisms in solar cells is important for further improvement in efficiency, especially for mesoscopic perovskite solar cells. Here, a two-dimensional modeling of the TiO2 nanowire-based organic–inorganic hybrid perovskite solar cells was performed combining the optical and electrical responses to reveal the impact of the properties of TiO2 nanowire array and absorber layer. Simulation results show a great dependence of device performance on the electron concentration of TiO2 nanowires, which decided the electron field distribution inside cells, and an optimum thickness of 600 nm is obtained for the TiO2 nanowires with low electron concentration. The collection of carriers is primarily within perovskite itself, and the ratio through TiO2 nanowire is less than 5%. These findings can facilitate device optimization and enhance the performance of the perovskite solar cells.