Potential lead-free small band gap halide double perovskites Cs2CuMCl6 (M = Sb, Bi) for green technology

Abstract Explorations of new stable lead free perovskites have currently achieved substantial interest in the field of photovoltaics and optoelectronics as it tries to overcome the instability issue and avoid toxicity related with the lead based perovskites. We herein not only comprehensively tried to explain the experimentally synthesized two inorganic halide double perovskite materials but exploring their broader structural stability and also provide us a guideline to better understand their possible potential applications. For this purpose we performed density functional theory to investigate the structural, electronic, optical, elastic and thermoelectric properties of these materials. The stability of these cubic materials is validated by optimizing the structure, from the tolerance factor, mechanical stability test. These materials are found to be small band gap semiconductors with outshining optoelectronic performance. Due to high optical absorption, high conductivity and low reflectivity they have great potential to be used as a light absorbing material for photovoltaic application. Because, of small band gap we also tried to explore the variation of various transport properties with chemical potential. The semiconducting nature of materials results in ZT close to unity predicting its excellent application in thermoelectric technology.

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Exploring the properties of lead-free hybrid double perovskites using a combined computational-experimental approach

Journal of Materials Chemistry A ◽

10.1039/c6ta05817e ◽

2016 ◽

Vol 4 (31) ◽

pp. 12025-12029 ◽

Cited By ~ 115

Author(s):

Zeyu Deng ◽

Fengxia Wei ◽

Shijing Sun ◽

Gregor Kieslich ◽

Anthony K. Cheetham ◽

...

Keyword(s):

Density Functional Theory ◽

Band Gap ◽

Density Functional ◽

Experimental Approach ◽

Lead Free ◽

Double Perovskites ◽

Functional Theory

Density functional theory screening of the hybrid double perovskites (MA)2BIBiX6 (BI = K, Cu, Ag, Tl; X = Cl, Br, I) was performed and (MA)2TlBiBr6, isoelectronic with MAPbBr3, was synthesised and found to have a band gap of ∼2.0 eV.

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Structure, Stability and Water Adsorption on Ultra-Thin TiO2 Supported on TiN

10.26434/chemrxiv.8425367.v1 ◽

2019 ◽

Author(s):

Jose Julio Gutierrez Moreno ◽

Marco Fronzi ◽

Pierre Lovera ◽

alan O'Riordan ◽

Mike J Ford ◽

...

Keyword(s):

Density Functional ◽

Water Adsorption ◽

Chemical Potential ◽

Energy Gap ◽

Molecular Water ◽

Structure Stability ◽

Ambient Conditions ◽

Rutile Structure ◽

The Stability ◽

The One

Interfacial metal-oxide systems with ultrathin oxide layers are of high interest for their use in catalysis. In this study, we present a density functional theory (DFT) investigation of the structure of ultrathin rutile layers (one and two TiO2 layers) supported on TiN and the stability of water on these interfacial structures. The rutile layers are stabilized on the TiN surface through the formation of interfacial Ti–O bonds. Charge transfer from the TiN substrate leads to the formation of reduced Ti3+ cations in TiO2. The structure of the one-layer oxide slab is strongly distorted at the interface, while the thicker TiO2 layer preserves the rutile structure. The energy cost for the formation of a single O vacancy in the one-layer oxide slab is only 0.5 eV with respect to the ideal interface. For the two-layer oxide slab, the introduction of several vacancies in an already non-stoichiometric system becomes progressively more favourable, which indicates the stability of the highly non-stoichiometric interfaces. Isolated water molecules dissociate when adsorbed at the TiO2 layers. At higher coverages the preference is for molecular water adsorption. Our ab initio thermodynamics calculations show the fully water covered stoichiometric models as the most stable structure at typical ambient conditions. Interfacial models with multiple vacancies are most stable at low (reducing) oxygen chemical potential values. A water monolayer adsorbs dissociatively on the highly distorted 2-layer TiO1.75-TiN interface, where the Ti3+ states lying above the top of the valence band contribute to a significant reduction of the energy gap compared to the stoichiometric TiO2-TiN model. Our results provide a guide for the design of novel interfacial systems containing ultrathin TiO2 with potential application as photocatalytic water splitting devices.

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Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

Scientific Reports ◽

10.1038/s41598-021-86145-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Muhammad Faizan ◽

K. C. Bhamu ◽

Ghulam Murtaza ◽

Xin He ◽

Neeraj Kulhari ◽

...

Keyword(s):

Optical Properties ◽

Band Gap ◽

First Principles ◽

Density Functional ◽

Perovskite Solar Cells ◽

Dielectric Constants ◽

Maximum Efficiency ◽

Exchange Potential ◽

Double Perovskites ◽

Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

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Lead-free double perovskites Cs2InCuCl6 and (CH3NH3)2InCuCl6: electronic, optical, and electrical properties

Nanoscale ◽

10.1039/c9nr01645g ◽

2019 ◽

Vol 11 (23) ◽

pp. 11173-11182 ◽

Cited By ~ 12

Author(s):

Hung Q. Pham ◽

Russell J. Holmes ◽

Eray S. Aydil ◽

Laura Gagliardi

Keyword(s):

Electrical Properties ◽

Band Gap ◽

Lead Free ◽

Double Perovskites ◽

Optical And Electrical Properties ◽

Optoelectronic Applications

Two indium-based double perovskites, Cs2InCuCl6 and (CH3NH3)2InCuCl6, were proposed as promising materials for photovoltaic and optoelectronic applications with a suitable band gap and exceptional optical and electrical properties.

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Novel III-V Nitride Polymorphs in the P42/mnm and Pbca Phases

Materials ◽

10.3390/ma13173743 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3743 ◽

Cited By ~ 1

Author(s):

Qingyang Fan ◽

Xin Ai ◽

Junni Zhou ◽

Xinhai Yu ◽

Wei Zhang ◽

...

Keyword(s):

Shear Modulus ◽

Bulk Modulus ◽

Band Gap ◽

Density Functional ◽

Mechanical Stability ◽

Elastic Anisotropy ◽

Wide Band ◽

Light Emitting ◽

Ultraviolet Detectors ◽

Direct Band

In this work, the elastic anisotropy, mechanical stability, and electronic properties for P42/mnm XN (XN = BN, AlN, GaN, and InN) and Pbca XN are researched based on density functional theory. Here, the XN in the P42/mnm and Pbca phases have a mechanic stability and dynamic stability. Compared with the Pnma phase and Pm-3n phase, the P42/mnm and Pbca phases have greater values of bulk modulus and shear modulus. The ratio of the bulk modulus (B), shear modulus (G), and Poisson’s ratio (v) of XN in the P42/mnm and Pbca phases are smaller than those for Pnma XN and Pm-3n XN, and larger than those for c-XN, indicating that Pnma XN and Pm-3n XN are more ductile than P42/mnm XN and Pbca XN, and that c-XN is more brittle than P42/mnm XN and Pbca XN. In addition, in the Pbca phases, XN can be considered a semiconductor material, while in the P42/mnm phase, GaN and InN have direct band-gap, and BN and AlN are indirect wide band gap materials. The novel III-V nitride polymorphs in the P42/mnm and Pbca phases may have great potential for application in visible light detectors, ultraviolet detectors, infrared detectors, and light-emitting diodes.

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First-Principles Study on Structural, Mechanical, Anisotropic, Electronic and Thermal Properties of III-Phosphides: XP (X = Al, Ga, or In) in the P6422 Phase

Materials ◽

10.3390/ma13030686 ◽

2020 ◽

Vol 13 (3) ◽

pp. 686 ◽

Cited By ~ 4

Author(s):

Junjie Miao ◽

Changchun Chai ◽

Wei Zhang ◽

Yanxing Song ◽

Yintang Yang

Keyword(s):

Thermal Properties ◽

High Temperature ◽

Band Gap ◽

Potential Application ◽

Density Functional ◽

Elastic Anisotropy ◽

Infrared Detector ◽

Phonon Spectra ◽

Indirect Band Gap ◽

The Stability

The structural, mechanical, electronic, and thermal properties, as well as the stability and elastic anisotropy, of XP (X = Al, Ga, or In) in the P6422 phase were studied via density functional theory (DFT) in this work. P6422-XP (X = Al, Ga, or In) are dynamically and thermodynamically stable via phonon spectra and enthalpy. At 0 GPa, P6422-XP (X = Al, Ga, or In) are more rigid than F 4 ¯ 3 m-XP (X = Al, Ga, or In), of which P6422-XP (X = Al or Ga) are brittle and P6422-InP is ductile. In the same plane (except for (001)-plane), P6422-AlP and P6422-InP exhibit the smallest and the largest anisotropy, respectively, and P6422-XP (X = Al, Ga, or In) is isotropic in the (001)-plane. In addition, Al, Ga, In, and P bonds bring different electrical properties: P6422-InP exhibits a direct band gap (0.42 eV) with potential application for an infrared detector, whereas P6422-XP (X = Al or Ga) exhibit indirect band gap (1.55 eV and 0.86 eV). At high temperature (approaching the melting point), the theoretical minimum thermal conductivities of P6422-XP (X = Al, Ga, or In) are AlP (1.338 W∙m−1∙K−1) > GaP (1.058 W∙m−1∙K−1) > InP (0.669 W∙m−1∙K−1), and are larger than those of F 4 ¯ 3 m-XP (X = Al, Ga, or In). Thus, P6422-XP (X = Al, Ga, or In) have high potential application at high temperature.

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First-principle study of the electronic structure and optical property of Nb-doped anatase TiO2

International Journal of Modern Physics B ◽

10.1142/s021797921450091x ◽

2014 ◽

Vol 28 (17) ◽

pp. 1450091

Author(s):

Q. Y. Hou ◽

Q. L. Liu ◽

C. W. Zhao ◽

Y. Zhang

Keyword(s):

Electronic Structure ◽

Optical Property ◽

Band Gap ◽

Absorption Edge ◽

Short Wavelength ◽

Density Functional ◽

Functional Theory ◽

Long Wavelength ◽

The Density Functional Theory ◽

The Stability

The absorption edge shifted to long wavelength direction and short wavelength direction of two opposite experimental conclusions have been reported, when the band-gap and absorption spectra of Nb -doped anatase TiO 2 were studied. In order to solve this contradiction, the electronic structure and the optical property of Nb heavy doped anatase TiO 2 have been studied by the first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory with +U method modification. The calculated results indicate that the higher the Nb -doping is, the higher the total energy is, the worse the stability is, the higher the formation energy is, the more difficult the doping is, the wider the optical band-gap is, the more obvious the absorption edge shifting to short wavelength direction is, the lower the absorptivity and the reflectivity is, which is in agreement with the experimental results. The reasonable interpretation of the contradiction has been reported in this paper, too.

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Structure, Stability and Water Adsorption on Ultra-Thin TiO2 Supported on TiN

10.26434/chemrxiv.8425367.v2 ◽

2019 ◽

Author(s):

Jose Julio Gutierrez Moreno ◽

Marco Fronzi ◽

Pierre Lovera ◽

alan O'Riordan ◽

Mike J Ford ◽

...

Keyword(s):

Density Functional ◽

Water Adsorption ◽

Chemical Potential ◽

Energy Gap ◽

Molecular Water ◽

Structure Stability ◽

Ambient Conditions ◽

Rutile Structure ◽

The Stability ◽

The One

Interfacial metal-oxide systems with ultrathin oxide layers are of high interest for their use in catalysis. In this study, we present a density functional theory (DFT) investigation of the structure of ultrathin rutile layers (one and two TiO2 layers) supported on TiN and the stability of water on these interfacial structures. The rutile layers are stabilized on the TiN surface through the formation of interfacial Ti–O bonds. Charge transfer from the TiN substrate leads to the formation of reduced Ti3+ cations in TiO2. The structure of the one-layer oxide slab is strongly distorted at the interface, while the thicker TiO2 layer preserves the rutile structure. The energy cost for the formation of a single O vacancy in the one-layer oxide slab is only 0.5 eV with respect to the ideal interface. For the two-layer oxide slab, the introduction of several vacancies in an already non-stoichiometric system becomes progressively more favourable, which indicates the stability of the highly non-stoichiometric interfaces. Isolated water molecules dissociate when adsorbed at the TiO2 layers. At higher coverages the preference is for molecular water adsorption. Our ab initio thermodynamics calculations show the fully water covered stoichiometric models as the most stable structure at typical ambient conditions. Interfacial models with multiple vacancies are most stable at low (reducing) oxygen chemical potential values. A water monolayer adsorbs dissociatively on the highly distorted 2-layer TiO1.75-TiN interface, where the Ti3+ states lying above the top of the valence band contribute to a significant reduction of the energy gap compared to the stoichiometric TiO2-TiN model. Our results provide a guide for the design of novel interfacial systems containing ultrathin TiO2 with potential application as photocatalytic water splitting devices.

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Thickness-induced band-gap engineering in lead-free double perovskite Cs2AgBiBr6for highly efficient photocatalysis

Physical Chemistry Chemical Physics ◽

10.1039/d0cp03919e ◽

2021 ◽

Author(s):

Bing-Hao Wang ◽

Bin Gao ◽

Jin-Rong Zhang ◽

Lang Chen ◽

Guo Jun-Kang ◽

...

Keyword(s):

Solar Cells ◽

Band Gap ◽

Double Perovskite ◽

Lead Free ◽

Double Perovskites ◽

Two Dimensional ◽

Band Gap Engineering ◽

Highly Efficient ◽

Photovoltaic Solar Cells

In recent years, two-dimensional (2D) lead-free double perovskites have been attracting much attention because of their unique performance for photovoltaic solar cells andphotocatalysis. Nonetheless, how the thickness affects the photoelectric...

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