Transparent electrode for monolithic perovskite/silicon-heterojunction two-terminal tandem solar cells

Monolithic perovskite/silicon tandem solar cells have the potential to outperform the efficiency of silicon devices. However, transparent electrode is one of the sensitive factors and challenges for realization of tandem device. Herein, we modify the thickness of buffer layer and sputtering power of transparent electrode for equilibrium between protection of underlying layers and conductivity of electrode. Furthermore, thickness of ITO transparent electrode is varied to realize the optical optimizations. Ultimately, we obtain a monolithic perovskite/silicon-heterojunction tandem solar cell yielding the matched short circuit current density of up to 15.11 mA/cm(2) measured without any anti-reflective foil. In addition, a bifacial solar cell is also presented based on the semi-transparent perovskite solar cell. These results clearly illustrate the impendency of optical utilization in perovskite/silicon tandem cells. It permits a further step towards the realization of high efficiency tandem solar cells beyond the single-junction silicon cell efficiency limit.