Valence band structure and band offset of 3C- and 4H-SiC studied by ballistic hole emission microscopy

Park, Kibog; Ding, Yun; Pelz, J. P.; Neudeck, Philip G.; Trunek, Andrew J.

doi:10.1063/1.2218302

Cited by 11 publications

(4 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As far as we are aware, no analogous DLTS peaks were detected in 3C-SiC. This could be explained if we consider that the valence band maxima of 3C-and 4H-SiC are essentially aligned (a small ∼60 meV offset has been measured [16]), and that the Langer-Heinrich rule applies to defects in different SiC polytypes [17], i.e., V C levels are approximately pinned to the vacuum level regardless of the polytype [18]. With this in mind, we estimate the (−2/0) transition of V C in 3C-SiC to be located at ∼0.3-0.4 eV above E c .…”

Section: Introductionmentioning

confidence: 89%

Anisotropic and plane-selective migration of the carbon vacancy in SiC: Theory and experiment

et al. 2019

View full text Add to dashboard Cite

We investigate the migration mechanism of the carbon vacancy (V C) in silicon carbide (SiC) using a combination of theoretical and experimental methodologies. The V C , commonly present even in state-of-the-art epitaxial SiC material, is known to be a carrier lifetime killer and therefore strongly detrimental to device performance. The desire for V C removal has prompted extensive investigations involving its stability and reactivity. Despite suggestions from theory that V C migrates exclusively on the C sublattice via vacancy-atom exchange, experimental support for such a picture is still unavailable. Moreover, the existence of two inequivalent locations for the vacancy in 4H-SiC [hexagonal, V C (h), and pseudocubic, V C (k)] and their consequences for V C migration have not been considered so far. The first part of the paper presents a theoretical study of V C migration in 3C-and 4H-SiC. We employ a combination of nudged elastic band (NEB) and dimer methods to identify the migration mechanisms, transition state geometries, and respective energy barriers for V C migration. In 3C-SiC, V C is found to migrate with an activation energy of E A = 4.0 eV. In 4H-SiC, on the other hand, we anticipate that V C migration is both anisotropic and basal-plane selective. The consequence of these effects is a slower diffusivity along the axial direction, with a predicted activation energy of E A = 4.2 eV, and a striking preference for basal migration within the h plane with a barrier of E A = 3.7 eV, to the detriment of the k-basal plane. Both effects are rationalized in terms of coordination and bond angle changes near the transition state. In the second part, we provide experimental data that corroborates the above theoretical picture. Anisotropic migration of V C in 4H-SiC is demonstrated by deep level transient spectroscopy (DLTS) depth profiling of the Z 1/2 electron trap in annealed samples that were subject to ion implantation. Activation energies of E A = (4.4 ± 0.3) eV and E A = (3.6 ± 0.3) eV were found for V C migration along the c and a directions, respectively, in excellent agreement with the analogous theoretical values. The corresponding prefactors of D 0 = 0.54 cm 2 /s and 0.017 cm 2 /s are in line with a simple jump process, as expected for a primary vacancy point defect.

show abstract

Section: Introductionmentioning

confidence: 89%

Anisotropic and plane-selective migration of the carbon vacancy in SiC: Theory and experiment

et al. 2019

View full text Add to dashboard Cite

show abstract

“…SiC is known to have more than 200 polytypes of different crystal structures. 39 3C-SiC with a zinc blende structure is shown in Scheme S1, † and its lattice constants are a = b = c = 0.4341 nm. The optimized 3C-SiC and B-doped 3C-SiC (Si 31 BC 32 , Si 15 BC 16 and Si 7 BC 8 ) simple cubic crystal structures are shown in Scheme S2(a)-(b), † where Si in the symmetrical positions of the 3C-SiC crystal cell has been substituted by B.…”

Section: Calculationsmentioning

confidence: 99%

B-doped 3C-SiC nanowires with a finned microstructure for efficient visible light-driven photocatalytic hydrogen production

et al. 2015

View full text Add to dashboard Cite

B-doped 3C-SiC nanowires have been synthesized via a facile and simple carbothermal reduction method at 1500 °C for 2 h in a flowing purified argon atmosphere. The obtained nanowires possess a single crystalline and finned microstructure with fins about 100-200 nm in diameter and 10-20 nm in thickness. The diameter of the inner core stem is about 80 nm on average. Due to the smaller band gap, the finned microstructure and the single crystalline nature, the B-doped 3C-SiC nanowires demonstrate efficient activity as high as 108.4 μmol h(-1) g(-1) for H2 production, which is about 20 times higher than that of 3C-SiC nanowhiskers and 2.6 times higher than the highest value reported in the literature for SiC materials.

show abstract

“…1 In comparison, many of experimental works have been reported on the conduction band offset (CBO) or valence band offset (VBO) of various heterojunction material systems. In these experimental studies, the commonly used experimental methods, for example, are current-voltage (I-V ) characteristics, [2][3][4][5] capacitance-voltage (C-V ) measurement 3 6 7 on the Schottky structures, deep level transient spectroscopy (DLTS) measurements 3 5 on both bulk and quantum well structures, photon energy dependent square root of photocurrent, 9 photo-reflectance measurement 10 on bulk heterojunction and quantum well structures, estimation of the CBO with the aid of mid-infrared intersubband absorption in multiple quantum well structures, 11 ballistic hole emission microscopy (BHEM) method, 12 emission spectra measured on multiple quantum wells, 13 and the standard X-ray photoelectron spectroscopy (XPS) measurement. [14][15][16][17][18][19][20][21][22][23][24] Among the all evaluation methods mentioned above, XPS is the most accurate one to determine the band offset.…”

Section: Introductionmentioning

confidence: 99%

Conduction and Valence Band Discontinuities in Some New Semiconductor Heterojunctions

Zhu

Ju²,

Li³

et al. 2011

j nanosci nanotechnol

View full text Add to dashboard Cite

Conduction and valence band discontinuities (band offsets) in the heterojunctions consisting of ZnO/4H-SiC, ZnO/GaAs, MgO/4H-SiC, MgO/AIN, InN/ZnO, InN/GaAs, MgO/InN, and InN/4H-SiC, were precisely determined by X-ray photoelectron spectroscopy (XPS) measurement. As an example, the XPS measurement on the ZnO/4H-SiC heterojunction is described in detail in the beginning of the section of the experiments. We also analyzed several factors which may have impact on the band offset in a practical heterojunction. The deviation in band offset induced by both polar and non-polar heterojunction band bending from the true value was also characterized by taking into account the intrinsic polarization field in the heterojunction consisting of the two polar materials.

show abstract

Valence band structure and band offset of 3C- and 4H-SiC studied by ballistic hole emission microscopy

Cited by 11 publications

References 24 publications

Anisotropic and plane-selective migration of the carbon vacancy in SiC: Theory and experiment

Anisotropic and plane-selective migration of the carbon vacancy in SiC: Theory and experiment

B-doped 3C-SiC nanowires with a finned microstructure for efficient visible light-driven photocatalytic hydrogen production

Conduction and Valence Band Discontinuities in Some New Semiconductor Heterojunctions

Contact Info

Product

Resources

About