Opto-electro-mechanical properties of lead-free hybrid double perovskites Cs2AgSbX6 (X = Cl, Br, I) for solar cells: A first-principles study

First-Principles Calculations to Investigate Direct-Band Novel Cobalt-Based Double Perovskite Materials for Optoelectronic Applications

“…Figure shows the absorption coefficient of the perovskites as well as the AM1.5 spectral irradiance with a purple curve, the latter is usually used as incident light energy standard for evaluating the performance of ground solar devices and modules. All materials have high and broad absorption with peak values around 5 × 10 4 cm –1 in the wavelength from 200 to 1000 nm . According to the analysis of ε 1 (ω), there are some forbidden photons shown in Figure as shaded regions of wavelength.…”

“…All materials have high and broad absorption with peak values around 5 × 10 4 cm −1 in the wavelength from 200 to 1000 nm. 87 According to the analysis of ε 1 (ω), there are some forbidden photons shown in Figure 5 as shaded regions of wavelength. To roughly measure the light absorption capacity of these materials and make a comparison, the integrated area of the absorption coefficient with respect to the wavelength (300−1200 nm, corresponding to the effective wavelength of AM1.5 spectrum) was consequently calculated except the above forbidden wavelength to the corresponding materials.…”

“…For example, through a high-throughput computational study, Cai et al made an explanation that among Cs 2 M 1 M 2 X 6 (M 1 = Cu, Ag, Au and M 2 = Al, Ga, In, Tl) double perovskites, and Ag-based materials had the largest band gaps due to the lowest energy of Ag d states . The conclusion also applies to other similar materials, such as Cs 2 AgSbCl 6 ( E g = 2.25 eV) and Cs 2 CuSbCl 6 ( E g = 1.29 eV). , Moreover, new materials with good prospects have been constantly found by this way, such as Cs 2 TlAsI 6 , Cs 2 InBiBr 6 , K 2 ScAgCl 6 , Cs 2 AgFeCl 6 , and so forth.…”

“…17 The conclusion also applies to other similar materials, such as Cs 2 AgSbCl 6 (E g = 2.25 eV) and Cs 2 CuSbCl 6 (E g = 1.29 eV). 18,19 Moreover, new materials with good prospects have been constantly found by this way, such as Cs 2 TlAsI 6 , 20 Cs 2 InBiBr 6 , 21 K 2 ScAgCl 6 , 22 Cs 2 AgFeCl 6 , 23 and so forth. Cobalt, an interesting transition element and widely used in oxides 24,25 and alloys, 26,27 was actually synthesized to be double halide perovskites, Rb 2 NaCoF 6 , Rb 2 KCoF 6 , and Cs 2 KCoF 6 since 1974.…”

New-Type Stable Double Perovskite Cs3CuAgI5 Single Crystal with Self-Trapping Exciton Emission for Optoelectronics

“…6 Darvish's team calculated the band gap and electronic and optical properties of Cs 2 AgSbX 6 double perovskite using firstprinciples density functional theory (DFT) and explored its optomechanical properties. 7 Giustino's team synthesized Cs 2 InAgCl 6 and Cs 2 AgInBr 6 . 8,9 The structure of double perovskite Cs 2 InAgCl 6 was unprecedented, with a measured band gap of 3.3 eV, and it was found that the compound was photosensitive and reversely changed from white to orange under ultraviolet irradiation.…”