Patterned Electrode Strategy for Advanced Light Management and Enhanced Photovoltaics Efficiency in Large-Area 4T Perovskite/Silicon Tandem Solar Modules

Abstract

Four-terminal (4T) perovskite/silicon tandem solar cells offer a promising route to surpass the thermodynamic Shockley–Queisser limit of silicon-based solar cells, enabling higher power conversion efficiencies (PCEs). However, due to current-spreading and shading issues, the efficiency of such devices tends to decrease significantly with increasing device area. In this architecture, the semitransparent perovskite top cell and electrode design play critical roles. In this study, we optimized the balance between optical transmittance and electrical conductivity by precisely controlling the oxygen content during the deposition of the transparent conductive oxide layer. This optimization significantly improved the photovoltaic performance of the perovskite module, achieving a champion PCE of 13.8% over a 4 cm² active area. Furthermore, we introduced an innovative metallization strategy, designated as “P2.5,” which involved localized gold deposition between sequential laser-scribing steps. This approach drastically reduced the contact resistance from 37.7 to 0.35 Ω, enhancing the module efficiency to 15.9%. To address the issue of optical shading induced by increased Au coverage, we implemented a patterned P2.5 configuration. This design preserved the top cell PCE at 15.5% while maintaining the filtered percentage of the bottom silicon cell at 43.4%. As a result, the 4T tandem module achieved an overall PCE of 26.1% over a 4 cm² active area, demonstrating one of the highest efficiencies among reported large-area 4T tandem devices with competitive scalability and light management.