All-Inorganic CsPbI₂Br Perovskite Solar Cells with High Efficiency Exceeding 13%

All-inorganic perovskite solar cells provide a promising solution to tackle the thermal instability problem of organic-inorganic perovskite solar cells (PSCs). Herein, we designed an all-inorganic perovskite solar cell with novel structure (FTO/NiO _x/CsPbI₂Br/ZnO@C₆₀/Ag), in which ZnO@C₆₀ bilayer was utilized as the electron-transporting layers that demonstrated high carrier extraction efficiency and low leakage loss. Consequently, the as-fabricated all-inorganic CsPbI₂Br perovskite solar cell yielded a power conversion efficiency (PCE) as high as 13.3% with a V_oc of 1.14 V, J_sc of 15.2 mA·cm^-2, and FF of 0.77. The corresponding stabilized power output (SPO) of the device was demonstrated to be ∼12% and remarkably stable within 1000 s. Importantly, the obtained all-inorganic PSCs without encapsulation exhibited only 20% PCE loss with thermal treatment at 85 °C for 360 h, which largely outperformed the organic-species-containing PSCs. The present study demonstrates potential in overcoming the intractable issue concerning the thermal instability of perovskite solar cells.