Two-dimensional exciton properties in monolayer semiconducting phosphorus allotropes

Author(s)

Villegas, Cesar E. P. ; Rodin, A. S. ; Carvalho, Alexandra ; Rocha, A. R.

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 18, n. 40, p. 27829-27836, OCT 28 2016.
• Web of Science Citations: 13

Abstract

Excitons play a key role in technological applications since they have a strong influence on determining the efficiency of photovoltaic devices. Recently, it has been shown that the allotropes of phosphorus possess an optical band gap that can be tuned over a wide range of values including the near-infrared and visible spectra, which would make them promising candidates for optoelectronic applications. In this work we carry out ab initio many-body perturbation theory calculations to study the excitonic effects on the optical properties of two-dimensional phosphorus allotropes: the case of blue and black monolayers. We elucidate the most relevant optical transitions, exciton binding energy spectrum as well as real-space exciton distribution, particularly focusing on the absorption spectrum dependence on the incident light polarization. In addition, based on our results, we use a set of effective hydrogenic models, in which the electron-hole Coulomb interaction is included to estimate exciton binding energies and radii. Our results show an excellent agreement between the many-body methodology and the effective models. (AU)

• FAPESP's process: 12/24227-1 - Optical properties and charge-transfer process studies for efficient organic photovoltaic cells: ab-initio simulations
• Grantee: César Enrique Pérez Villegas
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/14899-0 - Exciton-phonon coupling effects on the optical properties of semiconductors: an ab-initio density functional theory approach
• Grantee: César Enrique Pérez Villegas
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 11/11973-4 - ICTP South American Institute for Fundamental Research: a regional center for theoretical physics
• Grantee: Nathan Jacob Berkovits
• Support Opportunities: Research Projects - Thematic Grants