Optical study of narrow band gap<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>InAs</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mi>Sb</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>x</mml:mi><mml:mo>=</mml:mo><mml:mn>0</mml:mn></mml:mrow></mml:math>, 0.25, 0.5, 0.75, 1) alloys

Namjoo, Shirin; Rozatian, A. S. H.; Jabbari, Iraj; Puschnig, Peter

doi:10.1103/physrevb.91.205205

Cited by 18 publications

(13 citation statements)

References 30 publications

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“…The parent materials, (InAs and InSb), have the space group of F43m (216) with no inversion symmetry.The supercell structures, which result on doping the parent unit cell (F43m), acquire tetragonal (for x= 0.125, 0.50 and 0.875) and primitive cubic structures (for x= 0.25 and 0.75). Thus, the ternary alloys are treated as pseudo binary materials, where As is progressively replaced by Sb.The optimized lattice constants of InSb x As 1-x are obtained from Birch-Murnaghan29 fitting of energies with volume and they are in excellent match with other similar calculations 30.…”

supporting

confidence: 68%

“…Thus, the ternary alloys are treated as pseudo binary materials, where As is progressively replaced by Sb.The optimized lattice constants of InSb x As 1-x are obtained from Birch-Murnaghan 29 fitting of energies with volume and they are in excellent match with other similar calculations. 30 The calculated electronic structures at different k points of BZs of the compounds for x=0, 0.125, 0.25, 0.50, 0.75, 0.875 and 1 are shown in Fig. 5.…”

Section: Graded Fundamental Band Gap Along the Axis Of The Nws: As Me...mentioning

confidence: 99%

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Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire

2016

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Abstract:We report the graded electronic band gap along the axis of individual heterostructured WZ-ZB InAs/InSb 0.12 As 0.88 nanowires. Resonance Raman imaging has been exploited to map the axial variation in the second excitation gap energy (E 1 ) at the high symmetry point (L point) of the Brillouin zone. We relate the origin of the observed evolution of the gap energy to the fine tuning of the alloy composition from the tip towards the interface of the nanowire. The electronic band structures of InAs, InSb and InSb x As 1-x alloy systems at x=0.125, 0.25, 0.50, 0.75 and 0.875, using all electron density functional theory code Wien2k, are reported. The measured band gap along the axis of the InAs/InSb 0.12 As 0.88 nanowire is correlated with the calculated gap energy at the A point and the L point of the Brillouin zone for InAs and InSb 0.125 As 0.875 , respectively. We draw a one-to-one correspondence between the variation of the E 1 gap and the fundamental E 0 gap in the calculated electronic band structure and propose the graded fundamental gap energy across the axis of the nanowire.Keywords: Nanowire (NW), III-V axial heterostrucuture, resonance Raman mapping, composition variation, bandgap calculation  Email: anushree@phy.iitkgp.ernet.in 2The advancement of nanowire (NW) growth techniques opens a new horizon in the field of electronic band engineering. The fine tuning of the electronic band gap achieved by varying the composition 1 or strain in the crystal structure 2,3,4 in a single III-V semiconductor NW is of immense interest from both physics and application view points. For example, it has been shown that light emission from GaAs of wurtzite (WZ) phase can be controlled by varying external uniaxial stress on the NW. 4 On the other hand, the possible characteristics of InSb and InSb x As 1−x as topological insulators under stress or varying composition (x), has enhanced the interest in these systems from the physics point of view. 5,6The efficiency of InAs or InSb-based semiconductors to emit and detect long wavelength radiation harnesses the potential use of these systems in the fabrication of infra-red light sources (like lasers and LEDs) or detectors in optical communications and sensors. The need of finding an alternative of the most commonly used HgCdTe alloys as mid-infrared detectors, prompted researchers to investigate narrow band gap InSb and InSb x As 1−x ternary alloy systems. 7 TheInSbAs-based NWs are new state of art systems, which, in recent times have been of special interest due to the unavoidable modulation of alloy composition, axial strain 8,9,10 or defect states, 11 induced during the growth of a NW. All these factors are expected to fine tune the band gap along its axis. The above mentioned studies are the incentives for us to study the variation of the band gap in individual InAs/InSbAs heterostructured NW.In this work, we have demonstrated graded band gap in InAs/InSbAs NWs. The narrow band gap of InSbAs alloy, renders it difficult to study this system using conventional lumine...

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supporting

confidence: 68%

Section: Graded Fundamental Band Gap Along the Axis Of The Nws: As Me...mentioning

confidence: 99%

Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire

2016

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“…Соединения группы A 3 B 5 весьма популярны в при-кладных применениях и теоретических модельных ис-следованиях [1][2][3][4][5]. Наиболее изучены особенности лишь трех-четырех нижних зон проводимости (НЗП), а также оптические переходы в области до ∼ 10 эВ [1,3,[6][7][8][9][10][11][12].…”

Section: Introductionunclassified

“…Наиболее изучены особенности лишь трех-четырех нижних зон проводимости (НЗП), а также оптические переходы в области до ∼ 10 эВ [1,3,[6][7][8][9][10][11][12]. При энергии E > 10 эВ экспериментальные кривые от-ражения R(E) очень сильно понижаются, что суще-ственно затрудняет регистрацию их возможных сложных структур, связанных с переходами из остовных d-зон.…”

Section: Introductionunclassified

“…Это не связано с погрешностью в расчетах зон проводимости, так как после их смещения на δ s c погрешность составила ∼ 0.2 эВ, что заметно меньше разности в 0.4 эВ. Поэтому разумно предполо-жить, что такое отклонение связано с существованием метастабильных экситонов в области от ∼ 20 до ∼ 24 эВ с энергией связи ∼ 0.4 эВ, связанных с максимумами или ступеньками в межзонных переходах d → C 2 и d → C 3 .…”

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Сложная структура оптических переходов с остовных d-уровней кристаллов InAs и InSb

Соболев¹,

Perevoshchikov²

2017

Физика И Техника Полупроводников

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Усовершенствованным беспараметрическим методом объединенных диаграмм Арганда спектры диэлектри-ческой проницаемости кристаллов InAs и InSb в области 15−40 эВ разложены на тринадцать и двенадцать отдельных компонент соответственно с определением для каждой из них трех основных параметров: энергий максимума и полуширины, а также силы осциллятора. Силы осцилляторов находятся в интервалах 0.006−0.10 (InAs) и 0.014−0.076 (InSb). Спектры диэлектрических проницаемостей предварительно рассчи-таны на основе экспериментальных спектров отражения и поглощения методом интегральных соотношений Крамерса−Кронига. Предложена природа полученных полос переходов по модели межзонных и экситонных переходов. Цель настоящей работы состоит в моделировании полного набора оптических переходов кристаллов InAs и InSb в области 15−40 эВ при использовании эксперимен-тальных спектров отражения, поглощения и диэлектри-ческой проницаемости с последующим теоретическим анализом полученных данных на основе теоретических расчетов межзонных переходов и учета возможного вклада метастабильных экситонов.

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Charge‐Selective, Narrow‐Gap Indium Arsenide Quantum Dot Layer for Highly Stable and Efficient Organic Photovoltaics

Park

Bae

Kim

et al. 2022

Advanced Energy Materials

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The past decade has seen a dramatic surge in the power conversion efficiency (PCE) of next‐generation solution‐processed thin‐film solar cells rapidly closing the gap in PCE of commercially‐available photovoltaic (PV) cells. Yet the operational stability of such new PVs leaves a lot to be desired. Specifically, chemical reaction with absorbers via high‐energy photons transmitted through the typically‐adapted metal oxide electron transporting layers (ETLs), and photocatalytic degradation at interfaces are considered detrimental to the device performance. Herein, the authors introduce a device architecture using the narrow‐gap, Indium Arsenide colloidal quantum dots (CQDs) with discrete electronic states as an ETL in high‐efficiency solution‐processed PVs. High‐performing PM6:Y6 organic PVs (OPVs) achieve a PCE of 15.1%. More importantly, as the operating stability of the device is significantly improved, retaining above 80% of the original PCE over 1000 min under continuous illumination, a Newport‐certified PCE of 13.1% is reported for nonencapsulated OPVs measured under ambient air. Based on operando studies as well as optical simulations, it suggested that the InAs CQD ETLs with discrete energy states effectively cut‐off high‐energy photons while selectively collecting electrons from the absorber. The findings of this works enable high‐efficiency solution‐processed PVs with enhanced durability under operating conditions.

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Optical study of narrow band gapInAsxSb1−x(x=0, 0.25, 0.5, 0.75, 1) alloys

Cited by 18 publications

References 30 publications

Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire

Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire

Сложная структура оптических переходов с остовных d-уровней кристаллов InAs и InSb

Charge‐Selective, Narrow‐Gap Indium Arsenide Quantum Dot Layer for Highly Stable and Efficient Organic Photovoltaics

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Optical study of narrow band gapInAsxSb1−x(x=0, 0.25, 0.5, 0.75, 1) alloys

Cited by 18 publications

References 30 publications

Mapping of the electronic band gap along the axis of a single InAs/InSbxAs1−xheterostructured nanowire

Mapping of the electronic band gap along the axis of a single InAs/InSbxAs1−xheterostructured nanowire

Сложная структура оптических переходов с остовных d-уровней кристаллов InAs и InSb

Charge‐Selective, Narrow‐Gap Indium Arsenide Quantum Dot Layer for Highly Stable and Efficient Organic Photovoltaics

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Product

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Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire

Mapping of the electronic band gap along the axis of a single InAs/InSb_xAs_1−xheterostructured nanowire