Lead‐Free All‐Inorganic Indium Chloride Perovskite Variant Nanocrystals for Efficient Luminescence
Peigeng Han, Wei Zhou, Daoyuan Zheng, Xirui Zhang, Cheng Li, Qingkun Kong, Songqiu Yang, Ruifeng Lu, Keli Han
Abstract
Abstract Lead‐free halide perovskites and their variants have attracted great attention due to their non‐toxicity and good photophysical properties. Here, a series of undoped and antimony‐doped all‐inorganic, 0D, indium‐based perovskite variant nanocrystals (NCs): (Rb x Cs 1− x ) 3 InCl 6 and (Rb x Cs 1− x ) 3 InCl 6 :Sb (0 ≤ x ≤ 1) NCs, is reported. Among them, Sb‐doped NCs exhibit green emission. Mixing Rb‐Cs NCs show the higher photoluminescence (PL) quantum efficiency (PLQE) and better stability than unalloyed NCs ( x = 0 or 1). The effect of crystal size on PL property of (Rb 0.75 Cs 0.25 ) 3 InCl 6 :Sb is analyzed in detail. More interestingly, In‐based perovskite variant NCs containing coordinated water are successfully synthesized by a two‐step method (variable temperature hot injection and saturated steam post treatment). The best PLQE of Sb‐doped Cs 2 InCl 5 (H 2 O) NCs reaches 95.5%, which is a new PLQE record for yellow emissive lead‐free perovskite and variant NCs. In addition, the emission mechanism is further clarified by temperature‐dependent PL and femtosecond transient absorption techniques.