scholarly journals High Hole Mobility Polycrystalline GaSb Thin Films

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1348
Author(s):  
Anya Curran ◽  
Farzan Gity ◽  
Agnieszka Gocalinska ◽  
Enrica Mura ◽  
Roger E. Nagle ◽  
...  

In this paper, we report on the structural and electronic properties of polycrystalline gallium antimonide (poly-GaSb) films (50–250 nm) deposited on p+ Si/SiO2 by metalorganic vapour phase epitaxy at 475 °C. GaSb films grown on semi-insulating GaAs substrates are included as comparative samples. In all cases, the unintentionally doped GaSb is p-type, with a hole concentration in the range of 2 × 1016 to 2 × 1017 cm−3. Exceptional hole mobilities are measured for polycrystalline GaSb on SiO2 in the range of 9–66 cm2/Vs, exceeding the reported values for many other semiconductors grown at low temperatures. A mobility of 9.1 cm2/Vs is recorded for an amorphous GaSb layer in a poly-GaAs/amorphous GaSb heterostructure. Mechanisms limiting the mobility in the GaSb thin films are investigated. It is found that for the GaSb grown directly on GaAs, the mobility is phonon-limited, while the GaSb deposited directly on SiO2 has a Coulomb scattering limited mobility, and the poly-GaAs/amorphous GaSb heterostructure on SiO2 displays a mobility which is consistent with variable-range-hopping. GaSb films grown at low temperatures demonstrate a far greater potential for implementation in p-channel devices than for implementation in ICs.

2017 ◽  
Vol 2 (1) ◽  
pp. 60-64
Author(s):  
Yu-Feng Hsiou ◽  
Wei-Kuan Hung ◽  
Chiu-Wei Wang

In this work, antimony (Sb)-doped p-type ZnO thin films on c-plane sapphire substrates have been fabricated by pulsed laser deposition, with Sb2O3 used as the dopant source. The effects of ambient gas or growth temperature on the fabrication process were investigated. The nitrogen ambient was found to be essential to achieve the p-type conduction. The Hall-effect measurements at room temperature indicated that the ZnO thin films doped with 3 at.% Sb and grown at 600 °C under N2 atmosphere exhibited p-type behavior with a hole concentration of 1.17×1017 cm−3, hole mobility of 0.63 cm2/V·s, and resistivity of 84.51 Ω·cm. X-ray diffraction and scanning electron microscopy revealed good crystallization and homogenous surface morphology of the ZnO:Sb thin films. The optical transmission spectrum of the ZnO:Sb thin films indicated that the energy band gap value was around 2.9 eV. Post-growth annealing at 650 oC converted the p-type conduction to n-type. This result implied that Sb-doping and annealing treatment were dominant factors determining native and extrinsic defects in the ZnO thin films, and thus controlling their electrical conductivity properties.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5339
Author(s):  
Lian Zhang ◽  
Rong Wang ◽  
Zhe Liu ◽  
Zhe Cheng ◽  
Xiaodong Tong ◽  
...  

This work studied the regulation of hole concentration and mobility in p-InGaN layers grown by metalorganic chemical vapor deposition (MOCVD) under an N-rich environment. By adjusting the growth temperature, the hole concentration can be controlled between 6 × 1017/cm3 and 3 × 1019/cm3 with adjustable hole mobility from 3 to 16 cm2/V.s. These p-InGaN layers can meet different requirements of devices for hole concentration and mobility. First-principles defect calculations indicate that the p-type doping of InGaN at the N-rich limiting condition mainly originated from Mg substituting In (MgIn). In contrast with the compensation of nitrogen vacancy in p-type InGaN grown in a Ga-rich environment, the holes in p-type InGaN grown in an N-rich environment were mainly compensated by interstitial Mg (Mgi), which has very low formation energy.


2003 ◽  
Vol 798 ◽  
Author(s):  
D. J. As ◽  
D. G. Pacheco-Salazar ◽  
S. Potthast ◽  
K. Lischka

ABSTRACTP-type doping of cubic GaN by carbon is reported with maximum hole concentration of 2 6.1×1018cm-3and hole mobility of 23.5 cm /Vs at room temperature, respectively. The cubic GaN:C was grown by rf-plasma assisted molecular beam epitaxy (MBE) under Ga-rich growth conditions on a semiinsulating GaAs (001) substrate (3 inches wafer). E-beam evaporation of a graphite rode with an C-flux of 1×1012cm-2s-1was used for C-doping of the c-GaN. Optical microscopy, Hall-effect measurements and photoluminescence were performed to investigate the morphological, electrical and optical properties of cubic GaN:C. Under Ga-rich growth conditions most part of the carbon atoms were incorporated substitutially on N-site giving p-type conductivity. Our results verify that effective p-type doping of c-GaN can be achieved under extrem Ga excess.


2011 ◽  
Vol 99 (6) ◽  
pp. 062113 ◽  
Author(s):  
V. Gorge ◽  
Z. Djebbour ◽  
A. Migan-Dubois ◽  
C. Pareige ◽  
C. Longeaud ◽  
...  

2002 ◽  
Vol 192 (2) ◽  
pp. 453-455 ◽  
Author(s):  
S. Yamaguchi ◽  
Y. Iwamura ◽  
Y. Watanabe ◽  
M. Kosaki ◽  
Y. Yukawa ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Huu Phuc Dang ◽  
Quang Ho Luc ◽  
Tran Le ◽  
Van Hieu Le

Transparent Sb-doped tin oxide (ATO) thin films were fabricated on quartz glass substrates via a mixed (SnO2+ Sb2O3) ceramic target using direct current (DC) magnetron sputtering in ambient Ar gas at a working pressure of 2 × 10−3 torr. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Hall-effect, and UV-vis spectra measurements were performed to characterize the deposited films. The substrate temperature of the films was investigated in two ways: (1) films were annealed in Ar ambient gas after being deposited at room temperature or (2) they were deposited directly at different temperatures. The first process for fabricating the ATO films was found to be easier than the second process. The deposited films showed p-type electrical properties, a polycrystalline tetragonal rutile structure, and their average transmittance was greater than 80% in the visible light range at the optimum annealing temperature of 500°C. The best electrical properties of the film were obtained on a 10 wt% Sb2O3-doped SnO2target with a resistivity, hole concentration, and Hall mobility of 0.55 Ω·cm, 1.2 × 1019 cm−3, and 0.54 cm2V−1s−1, respectively.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3038 ◽  
Author(s):  
Ørnulf Nordseth ◽  
Raj Kumar ◽  
Kristin Bergum ◽  
Irinela Chilibon ◽  
Sean Erik Foss ◽  
...  

Cuprous oxide (Cu2O) is a p-type semiconductor with high optical absorption and a direct bandgap of about 2.1 eV, making it an attractive material for photovoltaic applications. For a high-performance photovoltaic device, the formation of low-resistivity contacts on Cu2O thin films is a prerequisite, which can be achieved by, for instance, nitrogen doping of Cu2O in order to increase the carrier concentration. In this work, nitrogen-doped p-type Cu2O thin films were prepared on quartz substrates by magnetron sputter deposition. By adding N2 gas during the deposition process, a nitrogen concentration of up to 2.3 × 1021 atoms/cm3 in the Cu2O thin films was achieved, as determined from secondary ion mass spectroscopy measurements. The effect of nitrogen doping on the structural, optical, and electrical properties of the Cu2O thin films was investigated. X-ray diffraction measurements suggest a preservation of the Cu2O phase for the nitrogen doped thin films, whereas spectrophotometric measurements show that the optical properties were not significantly altered by incorporation of nitrogen into the Cu2O matrix. A significant conductivity enhancement was achieved for the nitrogen-doped Cu2O thin films, based on Hall effect measurements, i.e., the hole concentration was increased from 4 × 1015 to 3 × 1019 cm−3 and the resistivity was reduced from 190 to 1.9 Ω⋅cm by adding nitrogen to the Cu2O thin films.


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