Near-Infrared Optical Response and Carrier Dynamics for High Photoconversion in Tellurene

Cesar E.P. Villegas, Alexandre R. Rocha

Research output: Contribution to journalArticlepeer-review

Abstract

Materials for applications in solar cells require a combination of features including an appropriate band gap and long relaxation times for photoexcited hot carriers. On the basis of ab initio many-body perturbation theory, including the spin-orbit interaction, we investigate the photocarrier generation and dynamics in α-tellurene. We show that photoexcited electrons are mainly generated in the near-infrared range, starting at 0.89 eV and forming excitons that are strongly bound, compared to its bulk counterpart, with a binding energy of 0.31 eV. We also explore the role of the electron-phonon interaction, finding that the electronic states in the first conduction band minimum couples weakly with phonons, yielding longer hot electron lifetimes (up to 70 fs) and mean free paths up to 37 nm. We also show that the extraction of hot holes may result in a challenging task as these carriers possess sub-3 nm mean free paths. We finally estimate that 1-nm-thick α-Te provides a short-circuit current density of 6.7 mA/cm2and a maximum power conversion efficiency of 4.4%, which highlights its potential for efficient photovoltaic device development.

Original languageEnglish
Pages (from-to)6129-6134
Number of pages6
JournalJournal of Physical Chemistry C
Volume126
Issue number14
DOIs
StatePublished - 14 Apr 2022

Bibliographical note

Funding Information:
C.E.P.V. acknowledges the financial support from Universidad Nacional Mayor de San Marcos-RR N 005753-2021, Project No. B21130941. A.R.R. acknowledges support from FAPESP (Project Nos. 2016/01343-7 and 2017/02317-2). This work uses the computational resources from GRID-UNESP.

Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.

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