Lead-Free, Water-Stable A Bi I Perovskites: Crystal Growth and Blue-Emitting Quantum Dots [A=CH NH , Cs , and (Rb Cs ) ].

Despite the great success in the increase in the power conversion efficiency of lead halide perovskite solar cells, the toxicity of lead and the unstable nature of the materials are still major concerns for their wider implementation at the industrial level. Herein, large-size single crystals (SCs) are developed in HI solution by using a temperature lowering method and nanocrystals (NCs) of A Bi I perovskites [where A=CH NH (MA) , Cs , and (Rb Cs ) ] are formed in ethanol (EtOH) and toluene (TOL). The stability of A Bi I perovskite is investigated by immersing the SCs for 24 h and pellets for 12 h in water. Moreover, the A Bi I perovskite NCs displays a promising photoluminescence quantum yield of 17.63 % and a long lifetime of 8.20 ns.