The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Weihua Lin. Portrait.

Weihua Lin

Postdoctoral fellow

Weihua Lin. Portrait.

Optimizing the quasi-equilibrium state of hot carriers in all-inorganic lead halide perovskite nanocrystals through Mn doping : fundamental dynamics and device perspectives

Author

  • Jie Meng
  • Zhenyun Lan
  • Weihua Lin
  • Mingli Liang
  • Xianshao Zou
  • Qian Zhao
  • Huifang Geng
  • Ivano E. Castelli
  • Sophie E. Canton
  • Tönu Pullerits
  • Kaibo Zheng
Show all

Summary, in English

Hot carrier (HC) cooling accounts for the significant energy loss in lead halide perovskite (LHP) solar cells. Here, we study HC relaxation dynamics in Mn-doped LHP CsPbI3 nanocrystals (NCs), combining transient absorption spectroscopy and density functional theory (DFT) calculations. We demonstrate that Mn2+ doping (1) enlarges the longitudinal optical (LO)-acoustic phonon bandgap, (2) enhances the electron-LO phonon coupling strength, and (3) adds HC relaxation pathways via Mn orbitals within the bands. The spectroscopic study shows that the HC cooling process is decelerated after doping under band-edge excitation due to the dominant phonon bandgap enlargement. When the excitation photon energy is larger than the optical bandgap and the Mn2+ transition gap, the doping accelerates the cooling rate owing to the dominant effect of enhanced carrier-phonon coupling and relaxation pathways. We demonstrate that such a phenomenon is optimal for the application of hot carrier solar cells. The enhanced electron-LO phonon coupling and accelerated cooling of high-temperature hot carriers efficiently establish a high-temperature thermal quasi-equilibrium where the excessive energy of the hot carriers is transferred to heat the cold carriers. On the other hand, the enlarged phononic band-gap prevents further cooling of such a quasi-equilibrium, which facilitates the energy conversion process. Our results manifest a straightforward methodology to optimize the HC dynamics for hot carrier solar cells by element doping. This journal is

Department/s

  • Chemical Physics
  • NanoLund: Centre for Nanoscience
  • eSSENCE: The e-Science Collaboration

Publishing year

2022-02-14

Language

English

Pages

1734-1745

Publication/Series

Chemical Science

Volume

13

Issue

6

Document type

Journal article

Publisher

Royal Society of Chemistry

Topic

  • Condensed Matter Physics (including Material Physics, Nano Physics)

Status

Published

ISBN/ISSN/Other

  • ISSN: 2041-6520