PhD defense of Marija Knezevic – Tuesday, June 13th 2023 in salle Magat

03 June 2023 par clavaguera
Marija Knezevic of the TEMiC group will defend her thesis on Tuesday, June 13th 2023 at 2:00 p.m.

“Photoactive composites for environment and energy”, supervised by Christophe Colbeau-Justin and Mohamed Nawfal Ghazzal.

The defense will be held on the 13th of June at 2 pm, in Salle Magat. The defense will be in English.

Abstract

Over the past decade, metal halide perovskites (MHPs, CsPbX3: X = Cl, Br, I) have been widely investigated as promising materials in optoelectronics and photovoltaics. From a fundamental point of view, MHPs represent valid candidates for photocatalysis due to their high photogenerated charge-carrier production and mobility, and their narrow and tunable band-gap energy. In this work, we propose designing a nanostructure where the MHP is coated with a stable and inert thin TiO2 overlayer (CsPbBr3-yXy @TiO2), to enhance charge-carrier separation lifetime, and photocatalytic performances. We first investigated structural and morphological properties of CsPbBr3-yXy and CsPbBr3-yXy @TiO2. We further studied charge-carrier dynamics of CsPbBr3-yXy along with interfacial electron transfer from CsPbBr3-yXy to TiO2 by means of transient absorption spectroscopy (TAS), time- resolved photoluminescence (TRPL), and time- resolved microwave conductivity (TRMC). In order to find the optimal bandgap configuration for the most efficient charge separation and injection, the anionic ratio was varied, and MHPs are doped with metals such as bismuth and copper. The photocatalytic efficiency of MHPs- based photocatalysts is assessed for hydrogen generation and toluene oxidation.

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