Tunable relativistic quasiparticle electronic and excitonic behavior of the FAPb(I_1-<i>x</i>Br<i>_x</i>)₃ alloy

Autor(en)

Zeeshan Muhammad, Peitao Liu, Rashid Ahmad, Saeid Jalali Asadabadi, Cesare Franchini, Iftikhar Ahmad

Abstrakt

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(en)

Computergestützte Materialphysik

Externe Organisation(en)

University of Malakand (UOM), University of Isfahan, Gomal University

Journal

Physical Chemistry Chemical Physics

Band

22

Seiten

11943-11955

Anzahl der Seiten

13

ISSN

1463-9076

DOI

https://doi.org/10.1039/d0cp00496k

Publikationsdatum

06-2020

Peer-reviewed

Ja

ÖFOS 2012

104017 Physikalische Chemie, 103006 Chemische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/7f7d8c12-5690-4964-95ee-faa888fad7eb