Terbium‐Doped and Dual‐Passivated γ‐CsPb(I<sub>1−</sub><i><sub>x</sub></i>Br<i><sub>x</sub></i>)<sub>3</sub> Inorganic Perovskite Solar Cells with Improved Air Thermal Stability and High Efficiency
Sawanta S. Mali, Jyoti V. Patil, Sachin R. Rondiya, Nelson Y. Dzade, Julian A. Steele, Mohammad Khaja Nazeeruddin, Pramod S. Patil, Chang Kook Hong
Abstract
Abstract Realizing photoactive and thermodynamically stable all‐inorganic perovskite solar cells (PSCs) remains a challenging task within halide perovskite photovoltaic (PV) research. Here, a dual strategy for realizing efficient inorganic mixed halide perovskite PV devices based on a terbium‐doped solar absorber, that is, CsPb 1− x Tb x I 2 Br, is reported, which undertakes a bulk and surface passivation treatment in the form of CsPb 1− x Tb x I 2 Br quantum dots, to maintain a photoactive γ‐phase under ambient conditions and with significantly improved operational stability. Devices fabricated from these air‐processed perovskite thin films exhibit an air‐stable power conversion efficiency (PCE) that reaches 17.51% (small‐area devices) with negligible hysteresis and maintains >90% of the initial efficiency when operating for 600 h under harsh environmental conditions, stemming from the combined effects of the dual‐protection strategy. This approach is further examined within large‐area PSC modules (19.8 cm 2 active area) to realize 10.94% PCE and >30 days ambient stability, as well as within low‐bandgap γ‐CsPb 0.95 Tb 0.05 I 2.5 Br 0.5 ( E g = 1.73 eV) materials, yielding 19.01% (18.43% certified) PCE.