Solution synthesis and phase control of inorganic perovskites for high-performance optoelectronic devices.

An efficient method to synthesize well-crystallized inorganic cesium lead halide perovskites (CsPbX3, X = I or Br) with high yield and high reproducibility was proposed. Notably, the as-prepared CsPbI3 in the yellow orthorhombic phase (y-CsPbI3) can be easily converted to the black cubic perovskite phase CsPbI3 (b-CsPbI3) after thermal annealing. Furthermore, two-terminal photodetectors and all-inorganic perovskite solar cells based on b-CsPbI3 were fabricated, exhibiting high performances.