Structural, Electronic, and Optical Properties of CsPb(Br 1-x Cl x ) 3 Perovskite: First-Principles Study with PBE-GGA and mBJ-GGA Methods

• Published in: Materials Vol. 13; no. 21; p. 4944
• Main Authors: Ghaithan, Hamid M, Alahmed, Zeyad A, Qaid, Saif M H, Aldwayyan, Abdullah S
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03-11-2020; MDPI
• Subjects: Agreements; Approximation; Chlorides; Composition effects; CsPb(Br1−xClx)3 perovskite; electronic properties; Energy; First principles; Linear functions; Mathematical analysis; Optical properties; Optoelectronic devices; PBE–GGA and mBJ–GGA; Perovskites; Photoabsorption; structural properties; Symmetry; Unit cell; structural properties; optical properties; PBE–GGA and mBJ–GGA; electronic properties; CsPb(Br1−xClx)3 perovskite
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13214944

The effect of halide composition on the structural, electronic, and optical properties of CsPb(Br
Cl
)
perovskite was investigated in this study. When the chloride (Cl) content of x was increased, the unit cell volume decreased with a linear function. Theoretical X-ray diffraction analyses showed that the peak (at 2θ = 30.4°) shifts to a larger angle (at 2θ = 31.9°) when the average fraction of the incorporated Cl increased. The energy bandgap (E
) was observed to increase with the increase in Cl concentration. For x = 0.00, 0.25, 0.33, 0.50, 0.66, 0.75, and 1.00, the E
values calculated using the Perdew-Burke-Ernzerhof potential were between 1.53 and 1.93 eV, while those calculated using the modified Becke-Johnson generalized gradient approximation (mBJ-GGA) potential were between 2.23 and 2.90 eV. The E
calculated using the mBJ-GGA method best matched the experimental values reported. The effective masses decreased with a concentration increase of Cl to 0.33 and then increased with a further increase in the concentration of Cl. Calculated photoabsorption coefficients show a blue shift of absorption at higher Cl content. The calculations indicate that CsPb(Br
Cl
)
perovskite could be used in optical and optoelectronic devices by partly replacing bromide with chloride.