Photovoltaic performances of CsPbI2Br solar cells are still lower than those of hybrid inorganic–organic perovskite solar cells, and researchers are exploring ways to improve their efficiencies. Due to its higher thermal stability in comparison with the generally studied hybrid inorganic–organic perovskites, all-inorganic CsPbI2Br has recently attracted great attention. By utilizing the combination of MnCl2 and ZnCl2 particles doping to modulate film growth, it is found that MnCl2 and ZnCl2 particles infiltrate into the holes of the CsPbI2Br lattice through the growth procedure, leading to suppressed nucleation and reduced growth rate. The combination assists to achieve higher CsPbI2Br crystalline grains for increased Jsc as high as 15.66 mA cm−2 and FF as large as 73.37%. It is indicated that a specific combination of ZnCl2-MnCl2 doping can fundamentally improve the film surface morphology, reduce trap density, and suppress the recombination of carriers. Consequently, power conversion efficiency (PCE) is significantly improved from 13.47 to 14.15% compared with the reference device without doping.

Due to their outstanding performance, low cost, ease of fabrication, diverse photonic, and optoelectronic applications, metal halides perovskite have attracted extensive interest in photodetector applications. Currently, devices made by metal oxides, metal sulfides, and 2D materials had achieved good responsivity, but suffered from high dark current, slow response speed, small on-off ratio, and poor stability. Whole performances of these photodetectors are not satisfactory. Here, a lateral perovskite (CH₃NH₃PbBr₃)/Ethanolamine/TiO₂ (in ethanol) trilayer photodetector is designed for achieving high performance. EA treatment enhances electron extraction and reduces undesired recombination. This trilayer device shows good performances with low dark current of 1.5 × 10⁻¹¹ A, high on-off ratio of 2700, high photodetectivity of 1.51 × 10¹² Jones, high responsivity of 0.13 A W⁻¹, and high stability, comparative to conventional single layer devices. This work provides the way to improve the performance of metal halide perovskite photodetectors.

Inorganic tin–lead perovskites with low bandgap (1.2–1.4 eV) are desired absorber materials for solar cells owing to their ideal bandgap and compositional stability. However, such tin–lead perovskites are currently subject to inferior power conversion efficiency (PCE) and the origin remains unclear. Here, for the first time, we report the metal-cation-derived unsynchronized crystallization behavior of inorganic tin–lead perovskite, exemplifying by a representative composition CsPb0.7Sn0.3I3. A tin-perovskite-targeted crystallization modulation agent, 1-(4-fluorophenyl) piperazine (1-4FP), is introduced to synchronize the B-site alloying through its strong targeted bonding with SnI2, resulting in substantially enhanced film quality with better morphology and photoelectrical properties. Furthermore, first-principles molecular dynamics simulations reveal that the agent regulates the crystallization route toward the pure phase of CsPb0.7Sn0.3I3 by suppressing the preforming of tin perovskite. With our proposed approach, the best device attains PCE of 17.55%, which is record-high for inorganic tin–lead perovskite solar cells. In addition, treated devices show excellent stability with only 10% and negligible loss after being exposed to 1 sun intensity for 700 h and being stored in N2 after over 4000 h, respectively. Our findings open a new avenue of crystallization route design in inorganic tin–lead perovskites, so as to obtaining high-quality perovskite films and associated solar cells.