Author(s): Lin, ML (Lin, Miao-Ling); Dhanabalan, B (Dhanabalan, Balaji); Biffi, G (Biffi, Giulia); Leng, YC (Leng, Yu-Chen); Kutkan, S (Kutkan, Seda); Arciniegas, MP (Arciniegas, Milena P.); Tan, PH (Tan, Ping-Heng); Krahne, R (Krahne, Roman)

Source: SMALL Article Number: 2106759 DOI: 10.1002/smll.202106759 Early Access Date: FEB 2022

Abstract: The soft hybrid organic-inorganic structure of two-dimensional layered perovskites (2DLPs) enables broadband emission at room temperature from a single material, which makes 2DLPs promising sources for solid-state white lighting, yet with low efficiency. The underlying photophysics involves self-trapping of excitons favored by distortions of the inorganic lattice and coupling to phonons, where the mechanism is still under debate. 2DLPs with different organic moieties and emission ranging from self-trapped exciton (STE)-dominated white light to blue band-edge photoluminescence are investigated. Detailed insights into the directional symmetries of phonon modes are gained using angle-resolved polarized Raman spectroscopy and are correlated to the temperature-dependence of the STE emission. It is demonstrated that weak STE bands at low-temperature are linked to in-plane phonons, and efficient room-temperature STE emission to more complex coupling to several phonon modes with out-of-plane components. Thereby, a unique view is provided into the lattice deformations and recombination dynamics that are key to designing more efficient materials.

Accession Number: WOS:000761229700001

PubMed ID: 35218284

Author Identifiers:

Author Web of Science ResearcherID ORCID Number

Krahne, Roman 0000-0003-0066-7019

TAN, Ping-Heng D-1137-2009 0000-0001-6575-1516

ISSN: 1613-6810

eISSN: 1613-6829

Full Text: https://onlinelibrary.wiley.com/doi/10.1002/smll.202106759