Photoluminescence Characteristics of Sn2+ and Ce3+-Doped Cs2SnCl6 Double-Perovskite Crystals

Abstract

In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6 double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2 as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [ S n S n 4 + 2 + +VCl] defect complex in the crystal is formed by Sn2+ substituting Sn4+. The number of defects formed by Sn2+ in the crystal decreases with Ce3+ content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [ S n S n 4 + 2 + +VCl] decreased. When Ce3+ is incorporated into the crystals, the defects of [ C e 3 + S n 4 + +VCl] and [ S n S n 4 + 2 + +VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6 double perovskite crystals.

Morphologically Controlled Synthesis of Cs2SnCl6 Perovskite Crystals and Their Photoluminescence Activity

“…As a kind of perovskite, Cs 2 SnCl 6 also exhibited highly efficient blue light emission originated from [Bi Sn + V Cl ] defect complex introduced by Bi 3+ [16], however, no report about the photoluminescence of the Cs 2 SnCl 6 crystal without dopants has been published except for the recent work [20] to the best of our knowledge. Figure 6a shows the PL spectra of the crystals prepared at 0.083 mol/L SnCl 2 solution and different HCl concentrations under 350 nm excitation; the PLE and PL spectra of the crystals in Figure 3g are shown in Figure 6b.…”

Air stable and highly efficient Bi3+-doped Cs2SnCl6 for blue light-emitting diodes

“…Therefore, non-toxic Sn-based perovskites could be an ideal alternative. 1,2 Sn 2+ -based CsSnCl 3 barely shows any optoelectronic application due to its low PLQY, oxidation, and humidity, 3 while Sn 4+ -based Cs 2 SnCl 6 exhibits high antioxidation stability along with promising optoelectronic properties. 1 Cs 2 SnCl 6 has a vacancy-ordered double perovskite structure with isolated [SnCl 6 ] 4À octahedra, improving the photoluminescence by quantum connement effect.…”

Defects and Their Passivation in Hybrid Halide Perovskites toward Solar Cell Applications

“…Here, the Ce 3+ ions have introduced (Ce 3+ Sn 4+ +V Cl ) and (Sn 2+ Sn 4+ +V Cl ) defects, promoting radiative recombination pathways and thereby increasing the PL intensity. [ 188 ]…”