Dual‐Band‐Tunable White‐Light Emission from Bi³⁺/Te⁴⁺ Emitters in Perovskite‐Derivative Cs₂SnCl₆ Microcrystals

Abstract

Luminescent metal halides have attracted considerable attention in next‐generation solid‐state lighting because of their superior optical properties and easy solution processibility. Herein, we report a new class of highly efficient and dual‐band‐tunable white‐light emitters based on Bi3+/Te4+ co‐doped perovskite derivative Cs2SnCl6 microcrystals. Owing to the strong electron‐phonon coupling and efficient energy transfer from Bi3+ to Te4+, the microcrystals exhibited broad dual‐band white‐light emission originating from the inter‐configurational 3P0,1→1S0 transitions of Bi3+ and Te4+, with good stability and a high photoluminescence (PL) quantum yield of up to 68.3 %. Specifically, a remarkable transition in Bi3+‐PL lifetime from milliseconds at 10 K to microseconds at 300 K was observed, as solid evidence for the isolated Bi3+ emission. These findings provide not only new insights into the excited‐state dynamics of Bi3+ and Te4+ in Cs2SnCl6, but also a general approach to achieve single‐composition white‐light emitters based on lead‐free metal halides through ns2‐metal ion co‐doping.

Dual Emission in Organic–Inorganic (C4H12N)2HfCl6 Perovskites via the Invocation of Bi3+/Te4+ Octahedron Clusters

“…where I(t) and I 0 denotes the luminescence intensity, A 1 and A 2 represent constants, and τ 1 and τ 2 represent different lifetimes of exponential components. As shown in Figure 3d− 31,32,37,47 Regarding the codoped sample, the lifetimes monitored at 475 and 588 nm are 1.25 and 1.29 μs, respectively. Figure 3e shows similar profiles to the singledoped sample.…”

“…36 Figure 1b shows the PXRD patterns for the as-prepared samples, which were matched well with the pristine (C 4 H 12 N) 2 HfCl 6 structure without any observable impurities, indicating high crystallinity and phase purity. 37 With the introduction of doped ions (Bi 3+ and Te 4+ ), the peak at 12.11°m oves to a small angle (Figure S1) because the ionic radius of Bi 3+ (1.03 Å) and Te 4+ (0.97 Å) is slightly larger than that of Hf 4+ (0.71 Å). Figures 1c,d S1).…”

High brightness and vibronic luminescent behavior of YAG:Mn4+/Ca2+ red phosphor for preparing phosphor-in-glass in white LED

“…The obtained results show that the luminescence decay process could be greatly accelerated by increasing the temperature. Based on the consideration of the biexponential decay characteristic for our phosphor, the luminescence decay process can be characterized by an effective lifetime τ eff , which is expressed using eqn (2): 39 where I ( t ) denotes the PL intensity as a function of time t and I max is the maximum PL intensity. The calculated lifetimes of Mn 4+ are in a mini-second range, which is attributed to the forbidden transition character of 2 E → 4 A 2 in Mn 4+ ions.…”

Revealing the Emission Mechanism in Sb3+-Doped All-Inorganic Cadmium Chloride Perovskite

“…Metal halide perovskite materials with efficient self-trapped exciton (STE) emissions are promising candidates for single-material white light sources owing to their unique optical properties, such as a substantial Stokes shift and ultrabroadband emission. − Recently, doping with ions having a n s outer electron configuration, such as Sn 2+ , Pb 2+ , Sb 3+ , Bi 3+ , and Te 4+ , has proved to be one of the most robust strategies to achieve highly efficient STE emission from all-inorganic perovskites. − Among the different dopants, Sb 3+ cations are particularly interesting because they confer diverse and stable optical emission properties to a variety of perovskite hosts. − To generate efficient STE emission at room temperature, a suitable all-inorganic host is usually required to provide a wide optical band to prevent self-absorption. In addition to homovalent substitution in trivalent (e.g., In 3+ ) B-site hosts, − high-performance STE emission was achieved by aliovalent substitution in divalent (e.g., Zn 2+ and Cd 2+ ) , or quadrivalent (e.g., Sn 4+ and Zr 4+ ) B-site hosts. − Despite extensive ongoing research on numerous Sb 3+ -doped metal halide systems, knowledge of the underlying mechanism of their STE emission is fragmentary.…”