Interface properties for GaAs/InGaAlP heterojunctions by the capacitance-voltage profiling technique

Watanabe, Mutsumi; Ohba, Yasuo

doi:10.1063/1.98028

Cited by 192 publications

(39 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results for a GaAs-on-InGaP interface are consistent with these values, although much greater uncertainty occurs in that case due to the presence of extrinsic (charged) surface states. Comparing our result to prior measurements of the band offsets, [10][11][12][13][14][15][16][17] we note that some spread exists in those values but our result is near the middle of that range. It is also notable that our values are in fairly good agreement with the theoretical results of Froyen et al 19 of 0.37 and 0.12 eV for the VB and CB, respectively.…”

Section: Discussionmentioning

confidence: 51%

“…9,10,11,12,13,14,15,16,17,18 Varying degrees of ordering in different samples could be one reason leading to these discrepancies of CB offset values, 19 with InGaP films grown by metal-organic chemical vapor deposition exhibiting more ordering than films grown by gas-source molecular beam epitaxy. 20,21 In addition, the heterointerface may also be InGaAs-like or GaP-like, thus providing another possible source of variation in band offset results.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Band offsets of InGaP∕GaAs heterojunctions by scanning tunneling spectroscopy

Yang

Feenstra

Semtsiv

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

Scanning tunneling microscopy and spectroscopy are used to study InGaP/GaAs heterojunctions with InGaAs-like interfaces. Band offsets are probed using conductance spectra, with tip-induced band bending accounted for using 3-dimensional electrostatic potential simulations together with a planar computation of the tunnel current. Curve fitting of theory to experiment is performed. Using an InGaP band gap of 1.90 eV, appropriate to the disordered InGaP alloy, a valence band offset of eV 01 . 0 38 . 0 ± is deduced along with the corresponding conduction band offset of eV 01 . 0 10 . 0 ± (type I band alignment).Published in J. Appl. Phys. 103, 073704 (2008).2

show abstract

Section: Discussionmentioning

confidence: 51%

Section: Introductionmentioning

confidence: 99%

Band offsets of InGaP∕GaAs heterojunctions by scanning tunneling spectroscopy

Yang

Feenstra

Semtsiv

et al. 2008

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…[2,4]), again type I. This difference between large and small offsets does not appear to be from an ordering effect.…”

mentioning

confidence: 96%

“…However, there exist discrepancies between band offsets results obtained by different techniques for samples grown by different methods/groups. It is known that properties of the interface depend sensitively on the detailed growth conditions [2][3][4][5][6]. Prior experimental techniques used in this system are not spatially resolved and in order to better understand this material system a study of the atomic-scale structural and electronic properties of the junctions is useful.…”

Section: Introductionmentioning

confidence: 99%

Cross-sectional scanning tunneling microscopy and spectroscopy of InGaP/GaAs heterojunctions

Yang

Feenstra

Semtsiv

et al. 2004

Applied Physics Letters

View full text Add to dashboard Cite

Compositionally abrupt InGaP/GaAs heterojunctions grown by gas-source molecular beam epitaxy have been investigated by cross-sectional scanning tunneling microscopy and spectroscopy. Images inside the InGaP layer show non-uniform In and Ga distribution. About 1.5 nm of transition region at the interfaces is observed, with indium carryover identified at the GaAs-on-InGaP interface. Spatially resolved tunneling spectra with nanometer spacing across the interface were acquired, from which band offsets (revealing that nearly all of band offset occurs in the valence band) were determined.Heterojunctions between In x Ga 1-x P (hereafter InGaP) and GaAs have attracted attention recently because of their device applications. It has been predicted and confirmed that this system should have a large fraction of the total energy gap discontinuity occurring in the valence band, which improves the electron injection efficiency of an heterojunction bipolar transistor (HBT) [1]. However, there exist discrepancies between band offsets results obtained by different techniques for samples grown by different methods/groups. It is known that properties of the interface depend sensitively on the detailed growth conditions [2][3][4][5][6]. Prior experimental techniques used in this system are not spatially resolved and in order to better understand this material system a study of the atomic-scale structural and electronic properties of the junctions is useful.In this work we use scanning tunneling spectroscopy (STS) to study the spatial variation of the InGaP/GaAs electronic band structure at nanometer length scales. The advantage of such work is that band offsets can be measured while simultaneously imaging the atomic-scale structural properties of the interfaces. Due to the experimental challenges of measuring band offsets by STS, there are only a few prior examples of such work, most notably on AlGaAs/GaAs [7]. Liu et al. have used cross-sectional STM to study the ordering effect of InGaP [8]. In this paper, we report cross-sectional STM and STS studies of compositionally abrupt InGaP/GaAs heterojunctions prepared by gassource molecular beam epitaxy (GSMBE). Images inside the InGaP layer reveal a random arrangement of In and Ga atom. This result is consistent with PL results and growth conditions for similar samples that indicate a nearly fully disordered InGaP layer [9]. It is found that GaAs-on-InGaP interface has a slightly wider transition region and more interface intermixing than the InGaP-on-GaAs interface. Both interfaces exhibit InGaAs-like properties. Indium outdiffusion from InGaP into GaAs at the GaAs-onPublished in Appl. Phys. Lett. 84, 227 (2004).

show abstract

“…Finally, the rapid increase of electron concentration is followed by the drastic decrease of carrier concentration down to below 1 × 10 16 cm -3 , two orders lower than its bulk concentration 2 × 10 18 cm -3 . This pheno-menon is ascribed to the carrier depletion in underlying GaN [14][15][16]. Such carrier depletion at the ZnO/GaN heterointerface has been commonly found in inverted structures (i.e.…”

mentioning

confidence: 99%

Electrical properties of ZnO/GaN heterostructures and photoresponsivity of ZnO layers

Suzuki

Makino

et al. 2006

Phys. Status Solidi (c)

View full text Add to dashboard Cite

We report on the electrical properties of ZnO/GaN heterostructures and the photoresponsivity of ZnO Schottky barrier diodes for the applications of heterojunction transistors and ultraviolet photodetectors, respectivly. ZnO/GaN heterostructures exhibit a large plateau region of 6.5 V in 10 kHz capacitance-voltage curves. Moreover, it is found that a high electron density of ~ 10 18 cm -3 is accumulated at the heterointerface in depth profile. ZnO Schottky barrier diodes show a rapid increase of photocurrent of ~ 10 2 A at the long-wavelength cutoff of 390 nm with maitaining stable diode characteristics. And, it is observed that ZnO Schottky barrier diodes respond to photosignal within 1 ~ 2 msec with a time constant of 0.35 msec. ZnO/GaN heterostructures are very attractive as heterojunction devices, because a large bandgap discontinuity at heterointerface is expected. Johnson et al. have reported that the valence band of GaN is estimated to be located at 0.6 eV above the valence band of ZnO based on the electron affinity rule [2]. Hong et al. have by using X-ray photoelectron spectroscopy observed that the ZnO/GaN heterointerface is made up of the type II band alignment with the valence-band offset of 0.8 eV [3]. Moreover, ZnO/GaN heterostructures also have attractive merits in the aspect of crystal growth. GaN is good choice for a template for ZnO growth, because ZnO is a closely lattice-matched material to GaN with a lattice mismatch of 1.8 % [4], which is ten times smaller than Al 2 O 3 that is normally used as a substrate for ZnO. In the case that GaN with Ga polarity is used as a template, the polarity of ZnO can also be easily controlled by changing preexposure conditions [5].ZnO is also very attractive as UV photodetecting devices, because its bandgap spans the spectral region ranging from 2.5 eV (496 nm) to 10.6 eV (124 nm) by alloying Oxide materials such as CdO, MgO, and BeO. Moreover, ZnO is more strong for radiation damage at the range of very short wavelength (< 200 nm) than Si and GaN, due to large radiation hardness [1].

show abstract

Interface properties for GaAs/InGaAlP heterojunctions by the capacitance-voltage profiling technique

Cited by 192 publications

References 8 publications

Band offsets of InGaP∕GaAs heterojunctions by scanning tunneling spectroscopy

Band offsets of InGaP∕GaAs heterojunctions by scanning tunneling spectroscopy

Cross-sectional scanning tunneling microscopy and spectroscopy of InGaP/GaAs heterojunctions

Electrical properties of ZnO/GaN heterostructures and photoresponsivity of ZnO layers

Contact Info

Product

Resources

About