Cathodoluminescence Studies of the Inhomogeneities in Sn-doped Ga<sub>2</sub>O<sub>3</sub> Nanowires

Maximenko, S. I.; Mazeina, Lena; Picard, Yoosuf N.; Freitas, Jaime A.; Bermudez, V. M.; Prokes, S. M.

doi:10.1021/nl901514k

Cited by 79 publications

(69 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, there are clear similarities, most noticeably for the state near E C À 4.4 eV, both in terms of bandgap location and in concentration. While this level could possibly be related to the vacancies given its position in the bandgap based on predictions by theoretical calculations, 42,43 it also aligns quite well with a previous DLOS signature seen on EFG material that has been suggested to possibly be related to self-trapped holes (STH). 11,44,45 Regardless, the very similar DLOS spectrum and concentration for this level detected in b-Ga 2 O 3 materials synthesized by very different methods implies a common source that appears to be less dependent on the large differences in growth methods, and more work is needed to fully understand the STH presence in DLOS measurements.…”

Section: Model/parametersupporting

confidence: 84%

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

Farzana

Ahmadi

Speck

et al. 2018

Journal of Applied Physics

104

View full text Add to dashboard Cite

Deep level defects were characterized in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy (PAMBE) using deep level optical spectroscopy (DLOS) and deep level transient (thermal) spectroscopy (DLTS) applied to Ni/β-Ga2O3:Ge (010) Schottky diodes that displayed Schottky barrier heights of 1.50 eV. DLOS revealed states at EC − 2.00 eV, EC − 3.25 eV, and EC − 4.37 eV with concentrations on the order of 1016 cm−3, and a lower concentration level at EC − 1.27 eV. In contrast to these states within the middle and lower parts of the bandgap probed by DLOS, DLTS measurements revealed much lower concentrations of states within the upper bandgap region at EC − 0.1 – 0.2 eV and EC − 0.98 eV. There was no evidence of the commonly observed trap state at ∼EC − 0.82 eV that has been reported to dominate the DLTS spectrum in substrate materials synthesized by melt-based growth methods such as edge defined film fed growth (EFG) and Czochralski methods [Zhang et al., Appl. Phys. Lett. 108, 052105 (2016) and Irmscher et al., J. Appl. Phys. 110, 063720 (2011)]. This strong sensitivity of defect incorporation on crystal growth method and conditions is unsurprising, which for PAMBE-grown β-Ga2O3:Ge manifests as a relatively “clean” upper part of the bandgap. However, the states at ∼EC − 0.98 eV, EC − 2.00 eV, and EC − 4.37 eV are reminiscent of similar findings from these earlier results on EFG-grown materials, suggesting that possible common sources might also be present irrespective of growth method.

show abstract

Section: Model/parametersupporting

confidence: 84%

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

Farzana

Ahmadi

Speck

et al. 2018

Journal of Applied Physics

104

View full text Add to dashboard Cite

show abstract

“…As discussed above for undoped Ga 2 O 3 nanowires, the peaks located at around 4.4 and 5.4 eV may be associated to the photoresponse of the Ga 2 O 3 host, while the peak centred at 3.9 eV could be related to the presence of Sn in the wires. Maximenko et al [28] calculated the density of states in Ga 2 O 3 : Sn, with Sn impurities substituting for Ga 3+ ions at tetrahedral sites. They ascertained that the energy levels associated to this dopant lie at 0.98 eV below the conduction band minimum, i.e.…”

Section: Resultsmentioning

confidence: 99%

β-Ga₂O₃ nanowires for an ultraviolet light selective frequency photodetector

López¹,

Castaldini²,

Cavallini³

et al. 2014

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The behaviour of β-Ga 2 O 3 nanowires as photoconductive material in deep ultraviolet photodetectors to operate in the energy range 3.0-6.2 eV has been investigated. The nanowires were grown by a catalyst-free thermal evaporation method on gallium oxide substrates. Photocurrent measurements have been carried out on both undoped and Sn-doped Ga 2 O 3 nanowires to evidence the influence of the dopant on the photodetector performances. The responsivity spectrum of single nanowires show maxima in the energy range 4.8-5.4 eV and a strong dependence on the pulse frequency of the excitation light has been observed for undoped nanowires. Our results show that the responsivity of β-Ga 2 O 3 nanowires can be controlled by tuning the chopper frequency of the excitation light and/or by doping of the nanowires. Non-linear behaviour in characteristic current-voltage curves has been observed for Ga 2 O 3 : Sn nanowires. The mechanism leading to this behaviour has been discussed and related to space-charged-limited current effects. In addition, the responsivity achieved by doped nanowires at lower bias is higher than for undoped ones.

show abstract

“…The correlation of CL with high-resolution TEM (HRTEM) and EBIC has been used to characterize defects, such as dislocations or stacking faults [43][44][45][46][47]. As for the variation of concentration/composition, the combination of CL with TEM, EDS or Auger spectroscopy can result in a better understanding of the origin of the luminescence [48,49]. Here, we illustrate this aspect by the analysis of europium doping of AlN using the combination of CL and EDS [14].…”

Section: Comparison With Other E-beam Techniquesmentioning

confidence: 99%

Low-energy cathodoluminescence microscopy for the characterization of nanostructures

Dierre

Yuan

Sekiguchi

2010

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

Spatially and spectrally resolved low-energy cathodoluminescence (CL) microscopy was applied to the characterization of nanostructures. CL has the advantage of revealing not only the presence of luminescence centers but also their spatial distribution. The use of electrons as an excitation source allows a direct comparison with other electron-beam techniques. Thus, CL is a powerful method to correlate luminescence with the sample structure and to clarify the origin of the luminescence. However, caution is needed in the quantitative analysis of CL measurements. In this review, the advantages of cathodoluminescence for qualitative analysis and disadvantages for quantitative analysis are presented on the example of nanostructures.

show abstract

Cathodoluminescence Studies of the Inhomogeneities in Sn-doped Ga₂O₃ Nanowires

Cited by 79 publications

References 33 publications

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

β-Ga₂O₃ nanowires for an ultraviolet light selective frequency photodetector

Low-energy cathodoluminescence microscopy for the characterization of nanostructures

Contact Info

Product

Resources

About

Cathodoluminescence Studies of the Inhomogeneities in Sn-doped Ga2O3 Nanowires

Cited by 79 publications

References 33 publications

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

β-Ga2O3 nanowires for an ultraviolet light selective frequency photodetector

Low-energy cathodoluminescence microscopy for the characterization of nanostructures

Contact Info

Product

Resources

About

Cathodoluminescence Studies of the Inhomogeneities in Sn-doped Ga₂O₃ Nanowires

β-Ga₂O₃ nanowires for an ultraviolet light selective frequency photodetector