Tunable relativistic quasiparticle electronic and excitonic behavior of the FAPb(I<sub>1-<i>x</i></sub>Br<i><sub>x</sub></i>)<sub>3</sub> alloy

Author(s)
Zeeshan Muhammad, Peitao Liu, Rashid Ahmad, Saeid Jalali Asadabadi, Cesare Franchini, Iftikhar Ahmad
Abstract

We study the structural, electronic, and excitonic properties of mixed FAPb(I

1−xBr

x)

30 ≤x≤ 1 alloys by first-principles density functional theory as well as quasiparticle GW and Bethe Salpeter equation (BSE) approaches with the inclusion of relativistic effects through spin orbit coupling. Our results show that the system volume decreases with increasing Br content. The quasiparticle band gaps vary from 1.47 eV for pure α-FAPbI

3to 2.20 eV for Br-rich α-FAPbBr

3and show stronger correlation with the structural changes. The optical property analysis reveals that the overall excitonic peaks are blue shifted with the Br fraction. Our results further reveal strong Br concentration dependence of the variation in the exciton binding energy (from 74 to 112 meV) and the carrier effective masses as well as the high frequency dielectric constants. These findings provide a way to tune the carrier transport properties of the material by doping, which could be utilized to improve the short circuit currents and power conversion efficiencies in multijunction solar cell devices.

Organisation(s)
Computational Materials Physics
External organisation(s)
University of Malakand (UOM), University of Isfahan, Gomal University
Journal
Physical Chemistry Chemical Physics
Volume
22
Pages
11943-11955
No. of pages
13
ISSN
1463-9076
DOI
https://doi.org/10.1039/d0cp00496k
Publication date
06-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
104017 Physical chemistry, 103006 Chemical physics
Keywords
ASJC Scopus subject areas
Physics and Astronomy(all), Physical and Theoretical Chemistry
Portal url
https://ucris.univie.ac.at/portal/en/publications/tunable-relativistic-quasiparticle-electronic-and-excitonic-behavior-of-the-fapbi1xbrx3-alloy(7f7d8c12-5690-4964-95ee-faa888fad7eb).html