Highly conductive and broadband transparent Zr-doped In2O3 as the front electrode for monolithic perovskite/silicon tandem solar cells

Perovskite/silicon tandem solar cells show great potential for commercialization because of their high power conversion efficiency (PCE). The optical loss originated from the transparent electrode is still a challenge to further improve the PCE of perovskite/silicon tandem solar cells. Here, we developed zirconium-doped indium oxide (IZrO), a material with low resistivity and high transmittance sputtered at room temperature. It possesses a high mobility of 29.6 cm²/(V·s), a low resistivity of 3.32 × 10⁻⁴ Ω·cm, and a low sheet resistance of 25.55 Ω·sq⁻¹ as well as a high average transmittance of 81.55% in a broadband of 400–1200 nm. Moreover, the work function (W_F = 4.33 eV) matches well with the energy level of Ag electrode and SnO₂ buffer layer in the P-I-N type tandem device. Compared with the previous zinc-doped indium oxide (IZO) transparent electrode device, the absolute efficiency of perovskite/silicon tandem devices based on IZrO electrode is about 0.6% higher. The champion P-I-N type perovskite/silicon tandem solar cells employing IZrO as the front conducts show efficiency of 28.28% (area of 0.5036 cm²).