Low threshold and efficient multiple exciton generation in halide perovskite nanocrystals.

ABSTRACT: Multiple exciton generation (MEG) or carrier multiplication, a process that spawns two or more electron-hole pairs from an absorbed high-energy photon (larger than two times bandgap energy E_g), is a promising way to augment the photocurrent and overcome the Shockley-Queisser limit. Conventional semiconductor nanocrystals, the forerunners, face severe challenges from fast hot-carrier cooling. Perovskite nanocrystals possess an intrinsic phonon bottleneck that prolongs slow hot-carrier cooling, transcending these limitations. Herein, we demonstrate enhanced MEG with 2.25E_g threshold and 75% slope efficiency in intermediate-confined colloidal formamidinium lead iodide nanocrystals, surpassing those in strongly confined lead sulfide or lead selenide incumbents. Efficient

SUBMITTER: Li M 

PROVIDER: S-EPMC6180109 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature