Interface roughness scattering in GaAs/AlAs quantum wells

Sakaki, H.; Noda, Takeshi; Hirakawa, Kazuhiko; Tanaka, Masaaki; Matsusue, T.

doi:10.1063/1.98305

Cited by 678 publications

(360 citation statements)

References 11 publications

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“…In GaAs-based quantum wells, interfacial roughness scattering can dominate 111 . In the case of graphene, Coulomb scattering is dominant over short-range scattering and surface roughness in the form of ripples 103 .…”

Section: Electrical Transport and Devicesmentioning

confidence: 99%

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides

et al. 2012

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699M any two-dimensional (2D) materials exist in bulk form as stacks of strongly bonded layers with weak interlayer attraction, allowing exfoliation into individual, atomically thin layers 1 . The form receiving the most attention today is graphene, the monolayer counterpart of graphite. The electronic band structure of graphene has a linear dispersion near the K point, and charge carriers can be described as massless Dirac fermions, providing scientists with an abundance of new physics 2,3 . Graphene is a unique example of an extremely thin electrical and thermal conductor 4 , with high carrier mobility 5 , and surprising molecular barrier properties 6,7 .Many other 2D materials are known, such as the TMDCs 8,9 , transition metal oxides including titania-and perovskite-based oxides 10,11 , and graphene analogues such as boron nitride (BN) 12,13 . In particular, TMDCs show a wide range of electronic, optical, mechanical, chemical and thermal properties that have been studied by researchers for decades 9,14,15 . There is at present a resurgence of scientific and engineering interest in TMDCs in their atomically thin 2D forms because of recent advances in sample preparation, optical detection, transfer and manipulation of 2D materials, and physical understanding of 2D materials learned from graphene.The 2D exfoliated versions of TMDCs offer properties that are complementary to yet distinct from those in graphene. Graphene displays an exceptionally high carrier mobility exceeding 10 6 cm 2 V -1 s -1 at 2 K (ref. 16) and exceeding 10 5 cm 2 V -1 s -1 at room temperature for devices encapsulated in BN dielectric layers 5 ; because pristine graphene lacks a bandgap, however, fieldeffect transistors (FETs) made from graphene cannot be effectively switched off and have low on/off switching ratios. Bandgaps can be engineered in graphene using nanostructuring [17][18][19] , chemical functionalization 20 and applying a high electric field to bilayer graphene 21 , but these methods add complexity and diminish mobility. In contrast, several 2D TMDCs possess sizable bandgaps around 1-2 eV (refs 9,14), promising interesting new FET and optoelectronic devices.TMDCs are a class of materials with the formula MX 2 , where M is a transition metal element from group IV (Ti, Zr, Hf and so on), group V (for instance V, Nb or Ta) or group VI (Mo, W and so on), and X is a chalcogen (S, Se or Te). These materials form layered structures of the form X-M-X, with the chalcogen atoms in two hexagonal planes separated by a plane of metal atoms, as shown in Fig. 1a. Adjacent layers are weakly held together to form the bulk crystal in a variety of polytypes, which vary in stacking orders and metal atom coordination, as shown in Fig. 1e. The overall symmetry of TMDCs is hexagonal or rhombohedral, and the metal atoms have octahedral or trigonal prismatic coordination. The electronic properties of TMDCs range from metallic to semiconducting, as summarized in Table 1. There are also TMDCs that exhibit exotic behaviours such as charge density waves ...

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Section: Electrical Transport and Devicesmentioning

confidence: 99%

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides

et al. 2012

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“…Due to the lack of detailed experimental information on the quality of our samples interfaces, we resorted to the standard [8,12,17] procedure of treating ∆ and Λ as fitting parameters. We deduced their values from the temperature dependence of the decay time in one structure (BF1499) and then used them in the calculation of the lifetimes of the other structure (BF1500), obtaining very good agreement with our measured data, as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…A tunability with barrier width has been demonstrated previously at energies above ω opt , where lifetimes varying between 20 ps and 35 ps were deduced from electroluminescence measurements for diagonal transitions in QC structures of pSi/SiGe [6]. However the transport properties in semiconductor quantum wells have also been shown [7][8][9][10][11][12] to be strongly influenced by the quality of the interfaces. Fluctuations in the well width due to the presence of nonideal surfaces result in local fluctuations of the carriers' confinement potential, which act as a scattering potential for the 2D carrier gas.…”

Section: Introductionmentioning

confidence: 92%

Interwell relaxation times inp−Si∕SiGeasymmetric quantum well structures: Role of interface roughness

et al. 2007

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Article:Califano, M., Vinh, N.Q., Phillips, P.J. et al. (10 more We report the direct determination of non-radiative lifetimes in Si/SiGe asymmetric quantum well structures designed to access spatially indirect (diagonal) interwell transitions between heavy-hole ground states, at photon energies below the optical phonon energy. We show both experimentally and theoretically, using a six-band k·p model and a time-domain rate equation scheme, that, for the interface quality currently achievable experimentally (with an average step height ≥ 1Å), interface roughness will dominate all other scattering processes up to about 200 K. By comparing our results obtained for two different structures we deduce that in this regime both barrier and well widths play an important role in the determination of the carrier lifetime. Comparison with recently published experimental and theoretical data obtained for mid-infrared GaAs/AlGaAs multiple quantum well systems leads us to the conclusion that the dominant role of interface roughness scattering at low temperature is a general feature of a wide range of semiconductor heterostructures not limited to IV-IV materials.PACS numbers:

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“…͑This effect has been named "wavefunction deformation scattering." [13][14][15] ͒ To examine the significance of wave function deformation scattering, we plot an energy versus transmission curve ͑dot-dashed͒ for the rough SNWT calculated by the uncoupled mode space ͑UMS͒ approach, 6 in which only the variations in the electron subbands are included while the deformation and coupling terms are discarded. The fact that the UMS approach significantly overestimates the transmission for the rough device infers that wave function deformation scattering dominates the transport.…”

Section: Applied Physics Lettersmentioning

confidence: 99%

Theoretical investigation of surface roughness scattering in silicon nanowire transistors

Wang

Polizzi

Ghosh

et al. 2005

Applied Physics Letters

146

106

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In this letter, we report a three-dimensional (3D) quantum mechanical simulation to investigate the effects of surface roughness scattering (SRS) on the device characteristics of Si nanowire transistors (SNWTs). We treat the microscopic structure of the Si/SiO 2 interface roughness directly by using a 3D finite element technique. The results show that 1) SRS reduces the electron density of states in the channel, which increases the SNWT threshold voltage, and 2) the SRS in SNWTs becomes more effective when more propagating modes are occupied, which implies that SRS is more important in planar metal-oxide-semiconductor field-effect-transistors with many transverse modes occupied than in small-diameter SNWTs with few modes conducting.

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Interface roughness scattering in GaAs/AlAs quantum wells

Cited by 678 publications

References 11 publications

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides

Interwell relaxation times inp−Si∕SiGeasymmetric quantum well structures: Role of interface roughness

Theoretical investigation of surface roughness scattering in silicon nanowire transistors

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