Indium doped CsPbI₃ films for inorganic perovskite solar cells with efficiency exceeding 17%

In recent years, all-inorganic perovskite materials have set off a research boom owing to features, such as good thermal stability, suitable bandgap, and fascinating optical properties. However, the power conversion efficiency (PCE) and the ambient stability of all-inorganic perovskite solar cells still remain a challenge. Herein, we investigate the effect of the addition of InI₃ into CsPbI₃ film on the corresponding device. InI₃ incorporation could retard the crystallization process and control the growth rate of CsPbI₃ polycrystalline films, yielding a high quality film with large grains and few voids. The increment in electrostatic potential and the reduction of carrier recombination enabled the open-circuit voltage of fabricated perovskite solar cell to be increased from 0.89 to 0.99 V. The champion device delivered a power conversion efficiency of 17.09%, which is higher than 14.36% for the reference device. And the InI₃-included solar cell without any encapsulation retained 77% of its original efficiency after 860 h aging at room temperature in N₂ condition.