Phonon-driven transient bandgap renormalization in perovskite single crystals.
Mater Horiz
; 10(10): 4192-4201, 2023 Oct 02.
Article
in En
| MEDLINE
| ID: mdl-37431707
ABSTRACT
Tailoring the electronic structure of perovskite materials on ultrafast timescales is expected to shed light on optimizing optoelectronic applications. However, the transient bandgap renormalization observed upon photoexcitation is commonly explained by many-body interactions of optically created electrons and holes, which shrink the original bandgap by a few tens of millielectronvolts with a sub-picosecond time constant, while the accompanying phonon-induced effect remains hitherto unexplored. Here we unravel a significant contribution of hot phonons in the photo-induced transient bandgap renormalization in MAPbBr3 single crystals, as evidenced by asymmetric spectral evolutions and transient reflection spectral shifts in the picosecond timescale. Moreover, we performed a spatiotemporal study upon optical excitation with time-resolved scanning electron microscopy and identified that the surface charge carrier diffusion and transient bandgap renormalization are strongly correlated in time. These findings highlight the need to re-evaluate current theories on photo-induced bandgap renormalization and provide a new approach for precisely controlling the optical and electronic properties of perovskite materials, enabling the design and fabrication of high-performance optoelectronic devices with exceptional efficiency and unique properties.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Type of study:
Prognostic_studies
Language:
En
Journal:
Mater Horiz
Year:
2023
Document type:
Article