Abstract
At present, Organic-inorganic hybrid methylammonium lead halide perovskites MAPbX3 (MA= CH3NH3; X = Cl, Br) have recently attract attention scientific researchers, as a promising candidate for photovoltaic and optoelectronic devices. We have studied the electronic structures and optical properties of perovskites CH3NH3PbBr3 and CH3NH3PbCl3, using density functional theory (DFT). These physical properties are calculated by CASTEP code, such as the band structures, total density of states (TDOS), absorption coefficient, refractive index and optical conductivity. The analysis of band gap shows that these two perovskites are semiconducting materials. Calculated absorption coefficient of CH3NH3PbBr3 and CH3NH3PbCl3 shows an absorption peak around 3.87 eV and 2.04 eV, respectively. The above results provide good agreement with experimental work for optoelectronic properties of CH3NH3PbBr3 and CH3NH3PbCl3 materials.
Highlights
Hybrid perovskites have drawn attention of researchers in the field of photovoltaics by their potential in high efficiency solar cells [1,2]
These physical properties are calculated by CASTEP code, such as the band structures, total density of states (TDOS), absorption coefficient, refractive index and optical conductivity
The generalized gradient approximation (GGA) approach was used to calculate the bandgap of MAPbBr3 and MAPbCl3 to increase the precision of the bandgap calculation of these compounds to its maximum
Summary
Hybrid perovskites have drawn attention of researchers in the field of photovoltaics by their potential in high efficiency solar cells [1,2]. The electronic and optical characteristics of two organic/inorganic hybrid lead-halide perovskites MAPbX3 (MA= CH3NH3; X= Br, Cl) were calculated using the CASTEP code. The CASTEP programme can simulate the physical characteristics of these two perovskites, including electrical and optical properties, using the functional theory of density. The generalized gradient approximation (GGA) parameterized by Wu-Cohen (WC), was used to optimize the network parameters, and determined the band gap, TDOS, absorption coefficient, dielectric function, refractive index and optical conductivity, in the energy range 0-6 eV. The structure of MAPbCl3 is tetragonal with P1 symmetry (a=b=8.217926Å, c=12.349893Å, α=β=γ=90°). The structures of these two perovskites are fully optimized by the total minimization of energy, and are represented in Fig. and Fig.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
