Band Anti-Crossing Model in Dilute-As GaNAs Alloys

Goodrich, Justin C.; Borovac, Damir; Tan, Chee-Keong; Tansu, Nelson

doi:10.1038/s41598-019-41286-y

Cited by 11 publications

(4 citation statements)

References 37 publications

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“…Theoretical work has supported these experimental results [27]. The alloy GaAs 1-x N x (x <0.05) has in fact a giant curvature parameter b (bowing) [28,29] Indeed, for GaAsN, b = 16 -20 eV, the gap of the GaAsN and the value of b depend on the nitrogen composition (N). The gap decreases rapidly, while the bowing b decreases with the increase in the nitrogen (N) composition [30][31].…”

Section: Introductionmentioning

confidence: 87%

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

Mazari

Ameur

Boumesjed

et al. 2021

ETN

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The GaAsN alloy has a great potential in the manufacture of the photovoltaic devices. A simple optimized GaAsN junction can reach conversion efficiency from > 20%, comparable with that reached by the best cells of die CISGS. Because the band gap of GaAsN can be modified from 1.4 eV to 3.4 eV by increasing the nitrogen content with multi-junction cells, it is theoretically possible to achieve the record performance 70% with this only material system, whereas the theoretical record in technology GaAs multi-junctions is less than 50%. The work presented in this paper concerns the study of photovoltaic cells based on GaAsN nitrided materials. The main objective is to optimize the front and base with their thickness and doping, on the electrical characteristic of the photovoltaic cell and subsequently its output parameters under solar illumination of AM1.5G. 54.1 % efficiency is predicted for this new GaAs1-xNx based on a simple single solar cell. This structure can also provide a fundamental solar cell unit for developing very high efficiency IBSC solar cell.

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Section: Introductionmentioning

confidence: 87%

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

Mazari

Ameur

Boumesjed

et al. 2021

ETN

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“…In some systems such as GaAsN, the band originating from the added nitrogen atoms, the so-called 'defect N state' [54,[96][97][98][99], is strongly dispersed under strain (see Figs. S3b and S4b).…”

Section: Protocol For Determining Bandgap Naturementioning

confidence: 99%

Accurate first-principle bandgap predictions in strain-engineered ternary III-V semiconductors

Badal¹,

Marcel²,

Hepp³

et al. 2023

Preprint

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Tuning the bandgap in ternary III-V semiconductors via modification of the composition or the strain in the material is a major approach for the design of optoelectronic materials. Experimental approaches screening a large range of possible target structures are hampered by the tremendous effort to optimize the material synthesis for every target structure. We present an approach based on density functional theory efficiently capable of providing the bandgap as a function of composition and strain. Using a specific density functional designed for accurate bandgap computation (TB09) together with a band unfolding procedure and special quasirandom structures, we develop a computational protocol efficiently able to predict bandgaps. The approach's accuracy is validated by comparison to selected experimental data. We thus map the phase space of composition and strain (we call this the 'bandgap phase diagram') for several important III-V compound semiconductors: GaAsP, GaAsN, GaPSb, GaAsSb, GaPBi, and GaAsBi. We show the application of these diagrams for identifying the most promising materials for device design. Furthermore, our computational protocol can easily be generalized to explore the vast chemical space of III-V materials with all other possible combinations of III-and V-elements.

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“…First of all, the bowing in bandgap can be portrayed by a single bowing coefficient (b = −1.45 eV) in the entire range of composition. A band-anticrossing model applicable to highly mismatched alloys (Ga 1−x In x N y As 1−y ) [46,47] cannot hence describe the evolution of bandgap Ni 1−x Cd x S alloys, since such a model yields a composition-dependent bowing parameter b. We then followed a well-documented approach by considering three factors, namely charge redistribution, volume deformation, and structural relaxation contributing separately to the phenomenon [17,48].…”

Section: Reverse Bandgap-bowing: An Insightmentioning

confidence: 99%

Reverse bandgap-bowing in nickel-cadmium sulfide alloys (Ni_1−xCd_xS) and its origin

Paramanik¹,

Chatterjee²,

Pal³

2021

J. Phys.: Condens. Matter

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We present evolution of band energies in α-NiS when alloyed with a cationic doping through isovalent cadmium (Cd2+). Optical bandgap of nickel-cadmium sulfide (Ni1−x Cd x S) alloys, as a deviation from the linear relationship or Vegard’s law, have exhibited a reverse bandgap-bowing in the form of downward-concave dependence. Such a phenomenon, which manifests as a negative value of bowing coefficient (b), is uncommon in chalcogenide alloys. In this work, we have deliberated on the origin of reverse bandgap-bowing in nickel-cadmium alloys and identified the band responsible for the bowing phenomenon. While thin-films of the alloys were formed through successive ionic layer adsorption and reaction method, tunnel conductance and thereby density of states of the materials were derived from scanning tunneling spectroscopy. The spectroscopy provided the variation of conduction and valence band-edges (CB and VB, respectively) with respect to the cadmium-content in Ni1−x Cd x S. The CB-edge of the alloys could be seen to remain mostly unaffected with increasing cadmium-content, since the band is composed of only the S 2p orbitals; the VB-energy, on the other hand, which forms due to an effective coupling between the metal d and the anion p orbitals, could be seen to be affected due to a p–d repulsion. Based on our experimental findings, we inferred that an antagonism between volume deformation and structural relaxation had resulted in the reverse bandgap-bowing in Ni1−x Cd x S alloys.

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Band Anti-Crossing Model in Dilute-As GaNAs Alloys

Cited by 11 publications

References 37 publications

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

Accurate first-principle bandgap predictions in strain-engineered ternary III-V semiconductors

Reverse bandgap-bowing in nickel-cadmium sulfide alloys (Ni_1−xCd_xS) and its origin

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Band Anti-Crossing Model in Dilute-As GaNAs Alloys

Cited by 11 publications

References 37 publications

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

GaAs1-xNx candidate material for a high efficiency based homojunction solar cell

Accurate first-principle bandgap predictions in strain-engineered ternary III-V semiconductors

Reverse bandgap-bowing in nickel-cadmium sulfide alloys (Ni1−x Cd x S) and its origin

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Reverse bandgap-bowing in nickel-cadmium sulfide alloys (Ni_1−xCd_xS) and its origin