Experimental and theoretical investigations of optical properties of GaN/AlGaN MQW nanostructures. Impact of built-in polarization fields

Esmaeili, Morteza; Gholami, Mohammad Reza; Haratizadeh, H.; Ḿonemar, B.; Holtz, Per-Olof; Kamiyama, Satoshi; Amano, Hiroshi; Akasaki, Isamu

doi:10.2478/s11772-009-0010-2

Cited by 6 publications

(3 citation statements)

References 24 publications

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“…Group-III nitride family and their alloys are suitable materials for optoelectronic applications in short wave length, high temperature, high frequency and high power electronic devices [1,2]. Rare-earth doped AlN and GaN are effectively used in photonic devices, electroluminescent devices (ELDs), diode lasers, medicine and health physics [3][4][5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Amin¹,

Ahmad²,

Maqbool³

et al. 2011

Journal of Applied Physics

181

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A theoretical study of Al 1−x Ga x N, based on the full-potential linearized augmented plane wave method, is used to investigate the variations in the bandgap, optical properties, and nonlinear behavior of the compound with the change in the Ga concentration. It is found that the bandgap decreases with the increase in Ga. A maximum value of 5.50 eV is determined for the bandgap of pure AlN, which reaches a minimum value of 3.0 eV when Al is completely replaced by Ga. The static index of refraction and dielectric constant decreases with the increase in the bandgap of the material, assigning a high index of refraction to pure GaN when compared to pure AlN. The refractive index drops below 1 for higher energy photons, larger than 14 eV. The group velocity of these photons is larger than the vacuum velocity of light. This astonishing result shows that at higher energies the optical properties of the material shifts from linear to nonlinear. Furthermore, frequency dependent reflectivity and absorption coefficients show that peak values of the absorption coefficient and reflectivity shift toward lower energy in the ultraviolet ͑UV͒ spectrum with the increase in Ga concentration. This comprehensive theoretical study of the optoelectronic properties predicts that the material can be effectively used in the optical devices working in the visible and UV spectrum.

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Section: Introductionmentioning

confidence: 99%

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Amin¹,

Ahmad²,

Maqbool³

et al. 2011

Journal of Applied Physics

181

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“…IXs were most extensively studied in GaAs-based QWs [2,5,[12][13][14][15][16], but recently their realisation in wide bandgap semiconductors such as GaN [17], and ZnO [18], has been considered. GaN/(Al,Ga)N and ZnO/(Zn,Mg)O wide QWs grown along the (0001) crystal axis, naturally exhibit built-in electric fields up to MV/cm [19,20], so that IXs are naturally created in the absence of any external electric field. Such IXs have binding energy of tens of meV, largely above the 4 meV reached in a typical GaAsbased structure [21,22].…”

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confidence: 99%

Room-Temperature Transport of Indirect Excitons in(Al,Ga)N/GaNQuantum Wells

et al. 2016

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We report on the exciton propagation in polar (Al,Ga)N/GaN quantum wells over several micrometers and up to room temperature. The key ingredient to achieve this result is the crystalline quality of GaN quantum wells (QWs) grown on GaN template substrate. By comparing microphotoluminescence images of two identical QWs grown on sapphire and on GaN, we reveal the twofold role played by GaN substrate in the transport of excitons. First, the lower threading dislocation densities in such structures yield higher exciton radiative efficiency, thus limiting nonradiative losses of propagating excitons. Second, the absence of the dielectric mismatch between the substrate and the epilayer strongly limits the photon guiding effect in the plane of the structure, making exciton transport easier to distinguish from photon propagation. Our results pave the way towards room-temperature gate-controlled exciton transport in wide-bandgap polar heterostructures. PACS numbers:1 arXiv:1603.00191v1 [cond-mat.mes-hall]

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“…[1][2][3][4][5][6] For optical systems, the gallium nitride (GaN), gallium phosphide (GaP), and their alloys are of great importance in making low cost, small size, and fast functional blue light-emitting diodes (LEDs), laser diodes, photodetectors, solar cell for visible light, and long-wavelength emitters. [7,8] The knowledge of the bandgap and its engineering during alloy formation is significant for understanding optical properties in a wide range of energy spectrum. The optical behaviors of compounds depend on their desities of states (DOSs) and their investigation is an effective tool for obtaining the true knowledge of electronic structures.…”

Section: Introductionmentioning

confidence: 99%

Ab-initio calculations of bandgap tuning of In_1–xGa _xy (y = N, P)alloys for optoelectronic applications

Rashid¹,

Jamil²,

Mahmood³

et al. 2021

Chinese Phys. B

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The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few decades. In the present article, the bandgap tuning and its influence on optical properties of In1–x Ga x N/P, where (x = 0.0, 0.25, 0.50, 0.75, and 1.0) alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method (FP-LAPW) and modified Becke and Johnson potentials (TB-mBJ). The direct bandgaps turn from 0.7 eV to 3.44 eV, and 1.41 eV to 2.32 eV for In1–x Ga x N/P alloys, which increases their potentials for optoelectronic devices. The optical properties are discussed such as dielectric constants, refraction, absorption, optical conductivity, and reflection. The light is polarized in the low energy region with minimum reflection. The absorption and optical conduction are maxima in the visible region, and they are shifted into the ultraviolet region by Ga doping. Moreover, static dielectric constant ε 1(0) is in line with the bandgap from Penn’s model.

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Experimental and theoretical investigations of optical properties of GaN/AlGaN MQW nanostructures. Impact of built-in polarization fields

Cited by 6 publications

References 24 publications

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Room-Temperature Transport of Indirect Excitons in(Al,Ga)N/GaNQuantum Wells

Ab-initio calculations of bandgap tuning of In_1–xGa _xy (y = N, P)alloys for optoelectronic applications

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Experimental and theoretical investigations of optical properties of GaN/AlGaN MQW nanostructures. Impact of built-in polarization fields

Cited by 6 publications

References 24 publications

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Ab initio study of the bandgap engineering of Al1−xGaxN for optoelectronic applications

Room-Temperature Transport of Indirect Excitons in(Al,Ga)N/GaNQuantum Wells

Ab-initio calculations of bandgap tuning of In1–x Ga xy (y = N, P)alloys for optoelectronic applications

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Ab-initio calculations of bandgap tuning of In_1–xGa _xy (y = N, P)alloys for optoelectronic applications