Excitation‐Dependent Emission in All‐Inorganic Lead‐Free Cs₂ScCl₅·H₂O Perovskite Crystals

Abstract

Low‐dimensional lead‐free metal halides have recently attracted a great deal of attention for their unique photoluminescence properties. In this work, a new all‐inorganic zero‐dimensional (0D) rare‐earth perovskite, namely Cs2ScCl5·H2O is reported. The 0D crystal exhibits a rare phenomenon of excitation‐wavelength dependent emission from blue‐green to white to yellow at room temperature. Spectroscopic characterizations indicate the tunable emission is originated from two distinct self‐trapped exciton states. In addition, the yellow emission quantum yield can be enhanced from 1.2% to ≈100% by doping Sb3+ ions into the crystal. The work not only presents a new all‐inorganic semiconductor with tunable emission colors, but also provides a design strategy for developing nontoxic and high‐performance light‐emitting materials.

Exciton–phonon coupling in alanine-based hybrid lead bromide

“…Those different radioactive recombination pathways can change the center and shape of the PL spectrum. Such behaviors were observed in totally inorganic perovskites 90 and hybrid perovskites with wide emission bands. 91–95…”

“…Those different radioactive recombination pathways can change the center and shape of the PL spectrum. Such behaviors were observed in totally inorganic perovskites 90 and hybrid perovskites with wide emission bands. [91][92][93][94][95] The main optical characteristic of self-trapped excitons is a broadband that leads to white light emission.…”

Efficient White Light Emission of 0D Lead-Free Indium-Based Halide Perovskite and the Intermediate State Promotion Mechanism of the Nonadiabatic Transition to Self-Trapped Exciton via Antimony(III) Cation Doping

“…25 The optical properties of (DETA)InBr 6 were characterized using UV−vis absorption and photoluminescence (PL) spectroscopy as well as time-resolved PL spectroscopy. The broad absorption band ranging from 330 to 450 nm is attributed to the electron transitions from the ground 1 S 0 to the excited states of In 3+ in the isolated (InBr 6 ) 3− octahedron 27 (Figure 2b). As shown in Figure 1a, the ground powder exhibits cold white-light as illustrated by the visible photo images under 365 nm UV light.…”

Lead-free hybrid indium perovskites with near-unity PLQY and white light emission using an Sb3+doping strategy

“…The energy levels of this ns 2 electronic configuration of Sb 3+ have been widely reported, namely the excited singlet state 1 P 1 and the triplet state 3P n (n = 0, 1, 2), and the ground state 1 S 0 . 47,48 From the perspective of transition rules, the transition from the ground state 1 S 0 to the excited state 1 P 1 is ascribed to the spin-orbit coupling effect, while part of the ground state 1 S 0 to the triplet state 3 P 1 transition requires lattice vibration and spin-orbit interaction. However, in general, the transitions from 1 S 0 to the triplet states 3 P 2 and 3 P 0 are forbidden, but their transitions can be assisted by lattice vibrations.…”