Hidden Photoexcitations Probed by Multipulse Photoluminescence

Summary, in English

Time-resolved photoluminescence is a validated method for tracking the photoexcited carrier dynamics in luminescent materials. This technique probes the photoluminescence decays upon a periodic excitation by short laser pulses. Herein, we show that this approach cannot directly detect hidden photoexcitations with much slower dynamics than the photoluminescence decay. We demonstrate a new method based on a multipulse excitation scheme that enables an unambiguous detection and an easily interpreted tracking of these hidden species. The multipulse excitation consists of a single pulse (Read) followed by a burst of many closely separated pulses (Write) and finally another single pulse (Read). To illustrate the efficacy of the Read-Write-Read excitation scheme, we apply it to metal halide perovskites to directly visualize carrier trapping, extract the concentration of trapped charges, and determine the rate constant of trap depopulation. The developed approach allows studying performance-limiting processes in energy devices using a versatile, highly applicable all-optical method.

• Author: Alexandr Marunchenko; Jitendra Kumar; Dmitry Tatarinov; Anatoly P. Pushkarev; Yana Vaynzof; Ivan G. Scheblykin
• Department/s: Chemical Physics; LU Profile Area: Light and Materials; NanoLund: Centre for Nanoscience; LTH Profile Area: Nanoscience and Semiconductor Technology; LTH Profile Area: Photon Science and Technology
• Publishing year: 2024
• Language: English
• Pages: 5898-5906
• Publication/Series: ACS Energy Letters
• Volume: 9
• Issue: 12
• Links: http://dx.doi.org/10.1021/acsenergylett.4c02404
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Atom and Molecular Physics and Optics
• Status: Published
• ISBN/ISSN/Other: ISSN: 2380-8195