High performance perovskite solar cells with sputtered niobium-doped indium tin oxide transparent electrodes

Indium tin oxide (ITO) is a promising transparent electrode material for stable and highly efficient perovskite solar cells (PSCs). However, further improvement in ITO performance critically constrains the stability and efficiency enhancement of PSCs. Although many doping strategies were carried out to enhance the performance of ITO, most of these ITO have not been further investigated as transparent electrodes for PSCs. In this study, niobium-doped ITO (ITO:Nb) transparent electrodes were deposited via magnetron sputtering at varying sputtering powers, and their influence on PSC device performance was investigated. The doping of Nb can change the band structure of ITO to present superior energy level alignment, which facilitates carrier transport. By adjusting the sputtering power, we found that ITO:Nb films deposited at 70 W showed a uniform, dense morphology with low surface roughness. These films achieved optimal photoelectric performance, with a resistivity of 3.12 × 10 −4  Ω·cm and an average transmittance of 90.00 %. Moreover, the PSC based on ITO:Nb transparent electrodes exhibits excellent efficiency and stability, achieving a power conversion efficiency of 22.26 % and retaining 85.38 % of its initial efficiency after 80 days of aging in unencapsulated ambient conditions. This work proposes a novel strategy for designing transparent electrodes, enhancing the efficiency and stability of PSCs.