Slow carrier relaxation in tin-based perovskite nanocrystals

被引：79

作者：

Dai, Linjie ^{[1
]}

Deng, Zeyu ^{[2
]}

Auras, Florian ^{[1
]}

Goodwin, Heather ^{[1
]}

Zhang, Zhilong ^{[1
]}

Walmsley, John C. ^{[2
]}

Bristowe, Paul D. ^{[2
]}

Deschler, Felix ^{[1
]}

Greenham, Neil C. ^{[1
]}

机构：

[1] Univ Cambridge, Cavendish Lab, Cambridge, England

[2] Univ Cambridge, Dept Mat Sci & Met, Cambridge, England

来源：

NATURE PHOTONICS | 2021年 / 15卷 / 09期

基金：

英国工程与自然科学研究理事会; 欧洲研究理事会;

关键词：

HALIDE PEROVSKITES; PHONON BOTTLENECK; IODIDE; DYNAMICS; ELECTRON; FORMAMIDINIUM; EFFICIENCY;

D O I：

10.1038/s41566-021-00847-2

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Tin-based perovskite nanocrystals with slower than usual relaxation dynamics holds promise for superior lead-free perovskite optoelectronic devices. The conversion efficiency of solar energy in semiconductors is fundamentally limited by ultrafast hot-carrier relaxation processes, and slowing down these processes is critical for improved energy harvesting. Here we report formamidinium tin iodide (FASnI(3)) nanocrystals where quantum confinement effects yield an evolution from a continuous band structure to separate energy states with decreasing nanocrystal size, as observed by transient absorption spectroscopy. The appearance of separate energy levels slows down the relaxation of hot carriers by two orders of magnitude at low injected carrier densities (<1 carrier pair per nanoparticle). The observed build up time of the ground-state bleach at the band edge is two orders of magnitude slower in FASnI(3) nanocrystals than in lead halide perovskite bulk and nanocrystals, which we attribute to a phonon bottleneck effect. Our results highlight the promise of lead-free perovskite nanocrystals for high-efficiency photovoltaic applications operating above the Shockley-Queisser limit.

引用

页码：696 / 702

页数：7

共 38 条

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