Hot Carrier Distribution Engineering by Alloying: Picking Elements for the Desired Purposes

Bubaš, Matej; Sancho-Parramon, Jordi (2024) Hot Carrier Distribution Engineering by Alloying: Picking Elements for the Desired Purposes. The Journal of Physical Chemistry C, 128 (9). pp. 3924-3934. ISSN 1932-7447

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Official URL: http://doi.org/10.1021/acs.jpcc.3c07135

Abstract

Metal alloys hold the promise of providing hot carrier generation distributions superior to pure metals in applications such as sensing, catalysis, and solar energy harvesting. Guidelines for finding the optimal alloy configuration for a target application require an understanding of the connection between alloy composition and hot carrier distribution. Here, we present a density functional theory (DFT)-based computational approach to investigate the photogenerated hot carrier distribution of metal alloys based on the joint density of states and the electronic structure. We classified the metals by their electronic structure into closed d-shell, open d-shell, p-block, and s-block elements. It is shown that combining closed d-shell elements enables modulation of the distribution of highly energetic holes typical of pure metals but also leads to hot carrier production by infrared (IR) light excitation and the appearance of highly energetic electrons due to band folding and splitting. This feature arises as an emergent property of alloying and is unveiled only when the hot carrier distribution computation takes momentum conservation into account. The combination of closed d-shell with open d-shell elements allows an abundant production of hot carriers in a broad energy range, while alloying a closed d-shell element with an s-block element opens the door to hot electron distribution skewed toward high-energy electrons. The combination of the d-shell with the p-block elements results in a moderate hot carrier distribution whose asymmetry can be tuned by composition. Overall, the obtained insights that connect alloy composition, band structure, and resulting carrier distribution provide a toolkit to match elements in an alloy for the deliberate engineering of hot carrier distribution.

Item Type:

Article

Uncontrolled Keywords:

metal alloys ; hot carriers ; density functional theory ; band structure

Subjects:

NATURAL SCIENCES > Chemistry > Physical Chemistry

Divisions:

Division of Materials Physics

Projects: