Light and Carrier Transportation Management in Transparent Electrode for Achieving over 30% Efficiency Perovskite/Silicon Tandem Solar Cells

Perovskite/silicon tandem solar cells have drawn widespread attention owing to their higher power conversion efficiency (PCE). However, reducing the reflection and parasitic absorption as much as possible in the transparent electrode is of considerable interest to promote the tandem device to obtain higher circuit current density (J_SC). Furthermore, the carrier vertical and lateral transport capability of transparent electrodes also affects the electrical performance of solar cells. Herein, we designed and realized a stacked structure of a columnar-equiaxed zirconium-doped indium oxide (IZrO) film. The optimal stacked IZrO thin film shows carrier density and mobility of 9.4 × 10²⁰ cm^-3 and 29.7 cm² V^-1 s^-1, respectively. Additionally, it also shows superior optical transmittance and lower parasitic absorption in the visible-to-near-infrared region. In addition, reflectance in the perovskite/c-Si tandem solar cell shows an obvious reduction after the application of a stacked IZrO transparent electrode because of the gradient refractive index. Finally, the stacked IZrO transparent electrode was incorporated into P-I-N-type perovskite/textured-silicon tandem solar cells, and the champion stacked IZrO-based device showed PCE of 30.12% with an active area of 1.05 cm².