The Role of the Atmosphere on the Photophysics of Ligand-Free. Lead-Halide Perovskite Nanocrystals.
María Morán-Pedroso a, Andrea Rubino a, Mauricio E. Calvo a, Juan P. Espinós a, Juan F. Galisteo-López a, Hernán Míguez a
a Instituto de Ciencia de Materiales de Sevilla. (CSICUniversidad de Sevilla), Calle Américo Vespucio, 49, Sevilla, Spain
Proceedings of Applied Light-Matter Interactions in Perovskite Semiconductors 2021 (ALMIPS2021)
Online, Spain, 2021 October 5th - 7th
Organizers: Rafael Sánchez Sánchez and Miguel Anaya
Poster, María Morán-Pedroso, 029
Publication date: 23rd September 2021

Lead Halide Perovskites (LHP) have attracted a lot of interest over the last decade due to their outstanding optical and electronic properties making them a highly relevant material for high efficiency optoelectronic devices, especially in photovoltaics. LHP nanocrystals (NCs) further exhibit a high photoluminescence (PL) quantum yield turning them into a highly relevant material for emission applications (LEDs, lasers). However, NCs are routinely processed in colloidal suspension which introduces some limitations. Ligands compromise the performance in a device (as they hamper charge transport) and, together with solvents, make it difficult to isolate their role when studying light-matter interaction in this nanosized material.

Herein we present a study on the photophysical properties of ligand-free LHP NCs grown within a nanostructured metal-oxide matrix (Figure. 1.a). Similar to previous studies on their bulk counterpart [1], LHP NCs undergo pronounced PL activation and darkening processes under illumination (Figure 1.b) which are strongly dependent on the surrounding atmosphere. Different crystal-sized samples are compared, from micrometric (thin films) to nanometric scale, in order to evaluate the morphology dependence.

Further, a model to fit the time evolution of PL is proposed where activation and darkening processes are assumed to take place simultaneously. Activation (kact) and darkening rates (kdecay) are obtained and their evolution with the amount of surrounding oxygen retrieved. These results lead us to conclude that photo-induced PL activation/darkening are mainly a volume/surface-related processes. [2].

Financial support of the Spanish Ministry of Science and Innovation under grant MAT2017-88584-R (AEI/FEDER,-UE) is gratefully acknowledged.

© Fundació Scito
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info