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arXiv · 2202.04909

Multiple exciton generation and giant external quantum efficiency in VO$_2$

S. R. Sahu·A. Tripathy·K. Dey·N. Mansuri·V. G. Sathe·D. K. Shukla
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Abstract

Multiple exciton generation (MEG) is a widely studied phenomenon in semiconductor nanocrystals and quantum dots wherein photo-excited carriers relax by generating additional electron-hole pairs. Here, we present the first experimental observation of MEG and the same leading to giant external quantum efficiency (EQE) in VO$_2$, a prototype strongly correlated material. By employing a photoexcitation (lamda ~ 488 nm) of ~ 4.2 times the bandgap, EQE in VO$_2$ is enhanced up to ~ 170 % at room temperature. Temperature dependent experiments exhibit the direct relation between MEG and strength of electron correlation and suggest that such a phenomenon could be exploited in large number of strongly correlated materials for high performance solar cell research in near future.

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S. R. Sahu, A. Tripathy, K. Dey, N. Mansuri, V. G. Sathe, D. K. Shukla. 2022-02-10. Multiple exciton generation and giant external quantum efficiency in VO$_2$. https://arxiv.org/abs/2202.04909

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