Pressure‐Induced Emission toward Harvesting Cold White Light from Warm White Light

Abstract

The pressure-induced emission (PIE) behavior of halide perovskites has attracted widespread attention and has potential application in pressure sensing.H owever,h ighpressure reversibility largely inhibits practical applications. Here,w ed escribe the emission enhancement and non-doping control of the color temperature in two-dimensional perovskite (C 6 H 5 CH 2 CH 2 NH 3 ) 2 PbCl 4 ((PEA) 2 PbCl 4 )n anocrystals (NCs) through high-pressure processing.Aremarkable 5times PIE was achieved at am ild pressure of 0.4 GPa, whichw as highly associated with the enhanced radiative recombination of self-trapped excitons.Ofparticular importance is the retention of the 1.6 times emission of dense (PEA) 2 PbCl 4 NCs upon the complete release of pressure,a ccompanied by ac olor change from "warm" (4403 K) to "cold" white light with 14295 K. The irreversible pressure-induced structural amorphization, which facilitates the remaining local distortion of inorganic Pb-Cl octahedra with respect to the steric hindrance of organic PEA + cations,s hould be greatly responsible for the quenched highefficiency photoluminescence.

Pressure-Driven Reverse Intersystem Crossing: New Path toward Bright Deep-Blue Emission of Lead-Free Halide Double Perovskites

“…Pressure, as a unique thermodynamic variable, provided a powerful means to study the structural and emissive behaviors of materials. , High-pressure studies were able to clarify many important scientific debates that cannot be solved at ambient conditions . In addition, high pressure on halide perovskites has also achieved the tunability of band gap, the textural coalescence of morphology, and the improvement of emissive performance. − Motivated by these works, we have extended the high-pressure effect to the double perovskite CNAICB with the aim of uncovering the origin of NE and trying to boost its emissive properties.…”

Self-trapped exciton emission and piezochromism in conventional 3D lead bromide perovskite nanocrystals under high pressure

“…22 Thus, PIE provides distinct advantages for light-emitting applications achievable by the design of structural distortion. [23][24][25][26] Localization of carriers resulting from a low electronic dimension and seriously distorted metal halide octahedra enhance the optical activity and binding energy of STEs. Therefore, the radiative recombination of STEs may also be activated in doped 3D perovskite materials with local carriers by continuously tuning the structural distortion with the assistance of a high-pressure method.…”

Transformation between the Dark and Bright Self-Trapped Excitons in Lead-Free Double-Perovskite Cs2NaBiCl6 under Pressure

“…High pressure, as a physical means differing from chemical tailoring, can be used to adjust the electronic structure and crystal structure without changing the chemical composition. − Recently, the high-pressure technique has been utilized to investigate the relationship between the structure and the properties for various types of perovskites. − For example, the dramatic changes in structures under compression could result in unexpected emission at room temperature. − However, most of these works have focused on the steady-state photophyscial properties, and the transient dynamic processes have not yet been revealed. The time-resolved PL and ultrafast transient absorption (TA) experiments can be used to investigate the transient dynamic processes, which is beneficial for revealing the mechanisms of these unexpected phenomena.…”