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

Abstract

Developing single-component materials with bright white emission is highly demanded for energy saving nowadays. Self-trapped exciton (STE) emission has been recently regarded as a robust way to generate intrinsic white...

Spacer Switched Two-Dimensional Tin Bromide Perovskites Leading to Ambient-Stable Near-Unity Photoluminescence Quantum Yield

“…With λ ex of 380 nm, the intensity of the yellow emission centered at ∼580 nm increases with temperature from 5 to 300 K, although below 100 K, a distinct PL emission centered at ∼440 nm is observed (Figure a,b). This emission band is likely due to the band edge (BE) emission, and the yellow emission arises from the STE, which is common in low-dimensional perovskites for emitting white light . The BE emission is due to emission from the spin and parity allowed 1 P 1 excited state to the 1 S 0 ground state, which is common for systems with ns 2 electronic configuration, here Sn 2+ (Figure c). , When the nonradiative electron capture by permanent deep traps and electron transfer to the STE state are reduced at temperatures less than 150 K, partial electron transfer can also occur from the 1 P 1 excited singlet state to the 3 P 1 triplet state, followed by emission from 3 P 1 to 1 S 0 .…”

Pressure Effect on Self-Trapped Exciton and Dopant Energy Transfer in Neodymium-Doped CsPbBr3 Perovskite Nanocrystals

“…The enhanced carrier's radiative recombination from STEs was caused by the increased quantity of STEs due to atomic distortion and led to the increase of the contribution of τ 2 to the average lifetime of CsPbBr 3 :Nd, which in this case was from 27.6 to 66.4% (Figure 4c). On the other hand, the suppression of the energy transfer from Nd 3+ levels to the energy band 33 reduced the contribution of τ 1 to the average lifetime, which in this case was from 72.4 to 33.5% (Figure 4c). Therefore, the pressure-induced carrier lifetime shortening should be considered an intrinsic phenomenon caused by rareearth-ion doping.…”

Spacer Switched Two Dimensional Tin Bromide Perovskites Leading to Ambient Stable Near Unity Photoluminescence Quantum Yield

“…With ex of 380 nm, the intensity of the yellow emission centered at ~580 nm increases with temperature from 5to 300 K, although below 100K, a distinct PL emission centered at ~440 nm is observed(Figure3a,b).This emission band is likely due to the band edge (BE) emission and the yellow emission arises from the STE, which is common in low-dimensional perovskites for emitting white light. 28 The BE emission is due to emission from the spin and parity allowed 1 P1 excited state to the 1 S0 ground state, which is common for systems with ns 2 electronic configuration, here Sn 2+ (Figure 3c). 29,30 When the non-radiative electron capture by permanent deep trapsand electron transfer to the STE state are reducedat temperatures less than 150K, partial electron transfer can also occur from 1 P1 excited singlet state to the 3 P1 triplet state, followed by emission from 3 P1 to 1 S0.The self-trapped states are created by the overlapped discrete energy states below the conduction band because of strong carrier-phonon coupling.…”