Scanning tunneling microscopy on unpinned<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mtext>GaN</mml:mtext><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mn>1</mml:mn><mml:mover accent="true"><mml:mn>1</mml:mn><mml:mo stretchy="false">¯</mml:mo></mml:mover><mml:mn>00</mml:mn></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math>surfaces: Invisibility of valence-band states

Ebert, Ph.; Иванова, Л. Д.; Eisele, H.

doi:10.1103/physrevb.80.085316

Cited by 22 publications

(7 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The disorder-induced states on the surface would likely have pinned the Fermi level in between the two levels, such that only (0/+) level is empty but the (+/++) level is filled. In that case, the absence of (+/++) level can be attributed to a limited transport capability for in-gap states below the Fermi level of n-type material [46]. For in-gap surface states above the Fermi level (positive voltages), electrons tunneling into the states can tunnel through the depletion region into CB states, and observable current is thus achieved.…”

Section: Calculational Methodologymentioning

confidence: 99%

See 1 more Smart Citation

Oxygen vacancies on SrO-terminatedSrTiO3(001)surfaces studied by scanning tunneling spectroscopy

et al. 2015

View full text Add to dashboard Cite

5The electronic structure of SrTiO 3 (001) surfaces was studied using scanning tunneling 6 spectroscopy and density-functional theory. With high dynamic range measurements, an in-gap 7 transition level was observed on SrO-terminated surfaces, at 2.7 eV above the valence band 8 maximum. The density of centers responsible for this level was found to increase with surface 9 segregation of oxygen vacancies and decrease with exposure to molecular oxygen. Based on 10 these finding, the level is attributed to surface O vacancies. A level at a similar energy is 11 predicted theoretically on SrO-terminated surfaces. For TiO 2 -terminated surfaces, no discrete in-12 gap state was observed, although one is predicted theoretically. This lack of signal is believed to

show abstract

Section: Calculational Methodologymentioning

confidence: 99%

“…2 and 3). This apparent lack of band edge is a common feature in STS studies of large bandgap materials [46]. It generally signifies band bending during the STS measurement, which can occur either due to the electric field between the tip and surface extending into the sample or due to surface charging by tunnel current.…”

Section: B Mbe-grown Surfacesmentioning

confidence: 99%

Oxygen vacancies on SrO-terminatedSrTiO3(001)surfaces studied by scanning tunneling spectroscopy

et al. 2015

View full text Add to dashboard Cite

show abstract

“…A lot of research work has discussed the behavior of dislocations in GaN, [7][8][9][10][11] and it has been proved that opencore screw dislocations have nanopipes at their center and that these nanopipes have a significant influence on the reverse-bias I-V characteristics. 12 This can also explain why the dark current becomes higher with increasing the screw dislocation densities in the GaN-based MSM photodetectors, since the nanopipes can act as electron transport paths resulting in the increase of the reverse-bias voltage current.…”

Section: Influence Of Threading Dislocations On Gan-based Metal-semicmentioning

confidence: 99%

Influence of threading dislocations on GaN-based metal-semiconductor-metal ultraviolet photodetectors

Sun

Song

et al. 2011

Applied Physics Letters

View full text Add to dashboard Cite

Articles you may be interested inPerformance improvement of GaN-based ultraviolet metal-semiconductor-metal photodetectors using chlorination surface treatment J. Vac. Sci. Technol. B 30, 031211 (2012); 10.1116/1.4711215 Effect of asymmetric Schottky barrier on GaN-based metal-semiconductor-metal ultraviolet detector Response of ultra-low dislocation density GaN photodetectors in the near-and vacuum-ultraviolet J. Appl. Phys. 95, 8275 (2004); 10.1063/1.1748855 GaN metal-semiconductor-metal ultraviolet photodetector with IrO 2 Schottky contact Appl. Phys. Lett. 81, 4655 (2002); 10.1063/1.1524035High-speed, low-noise metal-semiconductor-metal ultraviolet photodetectors based on GaN

show abstract

“…However, we consider it quite possible that the acceptor states are of insufficient density to permit observable current through them to be attained in the measurement, as found previously for other large-band-gap surfaces. 23,24 On the surface of STO, as just argued, acceptor states will be produced with the formation of nanolines. Such states accept electrons from the CB, producing upwards band bending in the semiconductor and a Fermi level position at the surface that is expected to lie within the acceptor band.…”

Section: Resultsmentioning

confidence: 95%

Growth and electronic properties of nanolines on TiO2-terminated SrTiO3(001) surfaces

Yan

Sitaputra

Skowroński

et al. 2017

Journal of Applied Physics

View full text Add to dashboard Cite

Surfaces of homoepitaxially grown TiO 2 -terminated SrTiO 3 (001) were studied in situ with scanning tunneling microscopy and spectroscopy. By controlling the Ti/Sr ratio, two-dimensional domains of highly ordered linear nanostructures, so-called "nanolines", are found to form on the surface. To further study how the surface structure affects the band structure, spectroscopic studies of these surfaces were performed. Our results reveal significantly more band bending for surfaces with the nanolines, indicative of an acceptor state associated with these features.Additionally, an in-gap state is observed on nanoline surfaces grown under high oxygen deficient conditions. This state appears to be the same as that observed previously, arising from the (++/+) transition level of surface oxygen vacancies. I. INTRODUCTIONAs a common complex-oxide substrate, SrTiO 3 has been intensely investigated for several decades. Since 2004 in particular, the SrTiO 3 surface has drawn particular attention from researchers owing to a discovery of a 2D electron gas (2DEG) at the interface of a complex-oxide heterostructures, i.e. LaAlO 3 (001)/SrTiO 3 (001). [1][2][3][4][5][6] In such heterostructures, where novel properties are found at the interface, it is important to be able to distinguish any contribution from the substrate, SrTiO 3 (STO), from those that are produced by formation of the epitaxial overlayer, LaAlO 3 (LAO). Therefore, it is crucial to have a complete material concerning the surface of the substrate immediately prior to the overlayer growth. Castell et al. demonstrated that by argon-ion sputtering and ultra-high-vacuum (UHV) annealing 7,8,9 (as well as by Ti deposition and subsequent oxidation), 10 the STO surface will form close-packed domains of linear features, denoted as nanolines. These features were shown to be composed of TiO 2 -derived complexes, and they thus provide new means for developing technologies for photocatalysis. 9 Those workers studied the electronic properties of the nanolines by x-ray photoelectron spectroscopy and density functional theory, 9 but a study of such properties by scanning tunneling spectroscopy (STS) has not been performed to date.It is well known that homoepitaxial growth by molecular beam epitaxy (MBE) can yield surfaces of high surface quality, and it enables fine control of their stoichiometry. In this work, we study MBE-grown TiO 2 -terminated SrTiO 3 (001) surfaces in situ using scanning tunneling microscopy (STM) and STS. With the combination of STM

show abstract

Scanning tunneling microscopy on unpinnedGaN(11¯00)surfaces: Invisibility of valence-band states

Cited by 22 publications

References 24 publications

Oxygen vacancies on SrO-terminatedSrTiO3(001)surfaces studied by scanning tunneling spectroscopy

Oxygen vacancies on SrO-terminatedSrTiO3(001)surfaces studied by scanning tunneling spectroscopy

Influence of threading dislocations on GaN-based metal-semiconductor-metal ultraviolet photodetectors

Growth and electronic properties of nanolines on TiO2-terminated SrTiO3(001) surfaces

Contact Info

Product

Resources

About