Formation of polarons in metal-oxide based solar absorber materials | Muhammad N. Huda | NCP21

Описание: The talk was delivered at the National Conference on Physics - 2021 (6 -7 August 2021) organized by Bangladesh Physical Society.

Title: Formation of polarons in metal-oxide based solar absorber materials
Speaker: Muhammad N. Huda
Affiliation: Department of physics, The University of Texas at Arlington, TX 76019, USA
Date: 07 August 2021

Abstract: For solar energy-based renewable energy technologies, solar absorber materials with efficient optical absorption and charge transport properties are required. Hydrogen production from water splitting via the photo-electrochemical (PEC) process remains one of the most promising green technologies. The key materials for this technology are the photo-electrocatalysts that are required to absorb sunlight, form electron-hole pairs and transport the charge carriers efficiently towards the liquid-semiconductor interface to split water molecules. Metal-oxides are thought to be the most stable materials under intense interfacial reactive conditions. However, the overall solar to hydrogen production efficiencies are not as high as expected, even for those with near-suitable bandgap energies. One of the main reasons is attributed to the poor transport properties in metal-oxides, especially in the 3d transition metal-oxides, where electrons are strongly correlated. In strongly correlated systems, electrons can interact with phonons to form polarons. In this presentation, representative metal-oxides photo-catalysts will be considered to demonstrate the polaron formation mechanism. From detailed electronic structure calculations by density functional theory (DFT) based methods, the polaronic states in metal-oxides will be depicted. We will show how these polaronic states affect the transport properties and the photovoltages of the PEC cell. We will also discuss how well these computational results compare with the recent experimental outcome. Computations were performed at the Texas Advanced Computing Center (TACC).