Pressure-Induced Optical Band Gap Transition in Methylammonium Lead Halide Perovskites

2019 ◽  
Vol 123 (19) ◽  
pp. 12423-12428 ◽  
Author(s):  
Soghra Mirershadi ◽  
Farhad Sattari ◽  
Shahla Golghasemi Sorkhabi ◽  
Amir Masoud Shokri
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Halide Perovskites ◽  
Lead Halide

First-Principle Study of the Structural, Electronic, and Optical Properties of Cubic Cesium Lead Halide Perovskites for Photovoltaic System

2020 ◽  
Vol 4 (2) ◽  
pp. 1-16
Author(s):  
Muhammad Waqas
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Density Functional ◽  
Covalent Bond ◽  
Wide Band ◽  
Photovoltaic System ◽  
Full Potential ◽  
Potential Applications ◽  
Halide Perovskites ◽  
Lead Halide

Lead halide perovskites have attracted considerable attention as optoelectronic materials because these materials have high photovoltaic conversion efficiency. The current study is based on Density Functional Theory (DFT). This theory was used to calculate the structural, optical, and electronic properties of the lead halide perovskites CsPbX3 (X = Chlorine (Cl), Bromine (Br), Iodine (I)) compounds . In order to calculate the above mentioned properties of cubic perovskites CsPbX3 (X = Cl, Br, I), Full Potential Linear Augmented Plane Wave (FP-LAPW) method was implemented in conjunction with DFT utilizing LDA, GGA-PBE and mBJ approximations. A good agreement was found between experimentally measured values and theoretically calculated lattice constants. These compounds have a direct and wide band gap located at the point of R-symmetry, while the band gap decreases from ‘Cl’ to ‘I’ down the group. The densities of electrons revealed a strong ionic bond between Cs and halides and a strong covalent bond between ‘Pb’ and (Cl, Br, and I). The dielectric functions (reflectivity, refractive indices, absorption coefficients), optical conductivities (real and imaginary part) and other optical properties indicated that these compounds have novel energy harvester applications. The modeling of these perovskite compounds shows that they have high absorption power and direct band gaps in visible ultraviolet range and it also shows that these compounds have potential applications in solar cells.

scholarly journals Band-gap tuning of lead halide perovskites using a sequential deposition process

2014 ◽  
Vol 2 (24) ◽  
pp. 9221-9225 ◽  
Author(s):  
Sneha A. Kulkarni ◽  
Tom Baikie ◽  
Pablo P. Boix ◽  
Natalia Yantara ◽  
Nripan Mathews ◽  
...  
Keyword(s):  
Band Gap ◽  
Deposition Process ◽  
Sequential Deposition ◽  
Halide Perovskites ◽  
Band Gap Tuning ◽  
Lead Halide

Demonstration of band-gap tuning of mixed anion lead halide perovskites (MAPb(I1−xBrx)2 (0 ≤ x ≤ 1)) by means of a sequential deposition process.

scholarly journals Electronic and optical properties of bulk and surface of CsPbBr3 inorganic halide perovskite a first principles DFT 1/2 approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammed Ezzeldien ◽  
Samah Al-Qaisi ◽  
Z. A. Alrowaili ◽  
Meshal Alzaid ◽  
E. Maskar ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Visible Spectrum ◽  
Ultra Violet ◽  
Electronic And Optical Properties ◽  
Direct Band ◽  
Halide Perovskites ◽  
Electro Magnetic ◽  
Experimental Findings ◽  
Lead Halide

AbstractThis work aims to test the effectiveness of newly developed DFT-1/2 functional in calculating the electronic and optical properties of inorganic lead halide perovskites CsPbBr3. Herein, from DFT-1/2 we have obtained the direct band gap of 2.36 eV and 3.82 eV for orthorhombic bulk and 001-surface, respectively. The calculated energy band gap is in qualitative agreement with the experimental findings. The bandgap of ultra-thin film of CsPbBr3 is found to be 3.82 eV, which is more than the expected range 1.23-3.10 eV. However, we have found that the bandgap can be reduced by increasing the surface thickness. Thus, the system under investigation looks promising for optoelectronic and photocatalysis applications, due to the bandgap matching and high optical absorption in UV–Vis (Ultra violet and visible spectrum) range of electro-magnetic(em) radiation.

scholarly journals Direct observation of mode-specific phonon-band gap coupling in methylammonium lead halide perovskites

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Heejae Kim ◽  
Johannes Hunger ◽  
Enrique Cánovas ◽  
Melike Karakus ◽  
Zoltán Mics ◽  
...  
Keyword(s):  
Band Gap ◽  
Direct Observation ◽  
Phonon Band ◽  
Halide Perovskites ◽  
Lead Halide ◽  
Gap Coupling

THERMAL TRANSPORT BEHAVIORS IN LEAD HALIDE PEROVSKITES

2018 ◽  
Author(s):  
Wee-Liat Ong ◽  
Giselle Elbaz ◽  
Evan A. Doud ◽  
Philip Kim ◽  
Daniel Paley ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Halide Perovskites ◽  
Lead Halide

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

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