English

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

Materials Science 2023-10-27 v3 Applied Physics

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 VO2_2, a prototype strongly correlated material. By employing a photoexcitation (lamda ~ 488 nm) of ~ 4.2 times the bandgap, EQE in VO2_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.

Keywords

Cite

@article{arxiv.2202.04909,
  title  = {Multiple exciton generation and giant external quantum efficiency in VO$_2$},
  author = {S. R. Sahu and A. Tripathy and K. Dey and N. Mansuri and V. G. Sathe and D. K. Shukla},
  journal= {arXiv preprint arXiv:2202.04909},
  year   = {2023}
}

Comments

New version is available at arXiv:2310.14835

R2 v1 2026-06-24T09:29:42.117Z