Low‐Temperature Atomic Layer Deposition of Hole Transport Layers for Enhanced Performance and Scalability in Textured Perovskite/Silicon Tandem Solar Cells

Abstract

AbstractPerovskite tandem solar cells on textured silicon hold potential for surpassing single‐junction limits and industrial compatibility. However, integrating hole‐transporting layers (HTLs) onto textured silicon poses challenges in conformal coating, low‐temperature fabrication, and perovskite solution process compatibility. Here, an atomic layer deposition (ALD) copper‐doping process is introduced to fabricate low‐temperature NiOx HTLs (ALD Cu:NiOx), tailored for textured tandems. Copper‐doping reduces hydroxyl group content and Ni3+ defects, addressing the challenge of enhancing hole conductivity while mitigating recombination loss. This advancement enables to lower the post‐annealing temperature from >300 to 200 °C, achieving compatibility with silicon heterojunction (SHJ) cells and boosting the power‐conversion efficiency (PCE) of 1.65‐eV p–i–n perovskite solar cells to 22.47%. Integrating ALD Cu:NiOx beneath conventional self‐assembled monolayer HTL on textured SHJ leads to notable PCE enhancements, from 28.6% to 30.5% for 1‐cm2 tandems (certified stabilized PCE of 30.04%) and from 23.9% to 26.4% for 8.89‐cm2 tandems. Following 1000 h of maximum‐power‐point (MPP) tracking, tandems maintain 95% of initial efficiency. Notably, losses in open‐circuit voltage and PCE due to area upscaling reduced by over 20%, attributed to ALD Cu:NiOx’s ability to enhance perovskite film wettability and minimize shunting on silicon pyramid texture, underscoring its impacts for textured tandem upscaling.