p-type in ZnO:N by codoping with Cr

2003 ◽  
Vol 786 ◽  
Author(s):  
E. Kaminska ◽  
A. Piotrowska ◽  
J. Kossut ◽  
R. Butkute ◽  
W. Dobrowolski ◽  
...  

ABSTRACTWe report on the fabrication of p-ZnO films by thermal oxidation of Zn3N2 deposited by reactive rf sputtering. With additional chromium doping we achieved p-type conductivity with the hole concentration ∼5×1017cm−3 and the mobility of 23.6 cm2/Vs at room temperature. We developed a method of surface passivation of p-ZnO that maintains its p-type conductivity over time-scale of months.

2009 ◽  
Vol 24 (5) ◽  
pp. 1785-1790 ◽  
Author(s):  
Eui-Jung Yun ◽  
Jin Woo Jung ◽  
Chae Il Cheon ◽  
Jeong Seog Kim ◽  
Young Hwan Han ◽  
...  

We report the realization of the p-type conductivity and the enhancement of the photoluminescence (PL) intensity in undoped ZnO films treated with high-energy (1 MeV) electron-beam irradiation (HEEBI), suggesting that the HEEBI process is compatible with a low-temperature requirement for the fabrication of transparent thin film transistors with good efficiency on a plastic substrate. The p-type conductivity of the films was revealed by the Hall, x-ray photoelectron spectroscopy, and PL measurements after being electron-irradiated in air at room temperature. The major acceptor-like defects were determined to be oxygen interstitial and zinc vacancy. A model was proposed in terms of O as well as Zn diffusion to explain the observed results. It was also observed that HEEBI treatment has little influence on the optical transmittance of ZnO films, whereas HEEBI treatment shifts the optical band gap toward the lower energy region from 3.29 to 3.28 eV.


2016 ◽  
Vol 857 ◽  
pp. 131-135
Author(s):  
Seung Hwan Park ◽  
Dong Cheol Oh ◽  
Chul Gyu Jhun ◽  
Seung Oh Han ◽  
Takafumi Yao

We report on the p-type conductivity control using N and Te codoping and thermal annealing in the ZnO films, heteroepitaxially grown on Al2O3 substrates and homoepitaxially grown on ZnO substrates by molecular-beam epitaxy, respectively. The N and Te codoping and the homoepitaxy effectively reduce the background electron concentration in ZnO films due to the suppression of various defect generation, and the thermal annealing causes the conductivity conversion from n-type to p-type due to the activation of N-related defects and the annihilation of donor-type defects. The p-type conductivity with a hole concentration of 1.61016 cm-3 and a hole mobility of 16 cm2/Vsec is obtained in the ZnO:N+T film grown on the Al2O3 substrate and the p-type conductivity with a hole concentration of 4.01016 cm-3 and a hole mobility of 11 cm2/Vsec is obtained in the ZnO:N+Te film grown on the ZnO substrate.


1996 ◽  
Vol 450 ◽  
Author(s):  
C. A. Wang ◽  
G. W. Turner ◽  
M. J. Manfra ◽  
H. K. Choi ◽  
D. L. Spears

ABSTRACTGai1−xInxASySb1-y (0.06 < x < 0.18, 0.05 < y < 0.14) epilayers were grown lattice-matched to GaSb substrates by low-pressure organometallic vapor phase epitaxy (OMVPE) using triethylgallium, trimethylindium, tertiarybutylarsine, and trimethylantimony. These epilayers have a mirror-like surface morphology, and exhibit room temperature photoluminescence (PL) with peak emission wavelengths (λP,300K) out to 2.4 μm. 4K PL spectra have a full width at half-maximum of 11 meV or less for λP,4K < 2.1 μm (λP,300K = 2.3 μm). Nominally undoped layers are p-type with typical 300K hole concentration of 9 × 1015 cm−3 and mobility ∼ 450 to 580 cm2/V-s for layers grown at 575°C. Doping studies are reported for the first time for GalnAsSb layers doped n type with diethyltellurium and p type with dimethylzinc. Test diodes of p-GalnAsSb/n-GaSb have an ideality factor that ranges from 1.1 to 1.3. A comparison of electrical, optical, and structural properties of epilayers grown by molecular beam epitaxy indicates OMVPE-grown layers are of comparable quality.


Author(s):  
Siziwe Gqoba ◽  
Rafael Rodrigues ◽  
Sharon Lerato Mphahlele ◽  
Zakhele Ndala ◽  
Mildred Airo ◽  
...  

Oleylamine capped WS2 nanostructures were successfully formed at 320 &deg;C via a relatively simple colloidal route. SEM and TEM analyses showed that the 3D nanoflowers that were initially formed disintegrated into 2D nanosheets after prolonged incubation. XPS and XRD analyses confirmed oxidation of WS2 into WO3. Sensors based on these oleylamine capped WS2 nanoflowers and nanosheets still showed a change in electrical response towards various concentrations of NH3 vapour at room temperature in a 25% relative humidity background despite the oxidation. The nanoflowers exhibited n-type response while the nanosheets displayed a p-type response towards NH3 exposure. The nanoflower based sensors showed better response to NH3 vapour exposure than the nanosheets. The sensors showed a good selectivity towards NH3 relative to acetone, ethanol, chloroform and toluene. Meanwhile, a strong interference of humidity to the NH3 response was displayed at high relative humidity levels. The results demonstrated that oleylamine limited the extent of oxidation of WS2 nanostructures. The superior sensing performance of the nanoflowers can be attributed to their hierarchical morphology which enhances the surface area and diffusion of the analyte.


2017 ◽  
Vol 51 (5) ◽  
pp. 559-564 ◽  
Author(s):  
M. M. Mezdrogina ◽  
A. Ya. Vinogradov ◽  
V. S. Levitskii ◽  
E. E. Terukova ◽  
Yu. V. Kozhanova ◽  
...  

2002 ◽  
Vol 744 ◽  
Author(s):  
Lihua Bai ◽  
N. Y. Garces ◽  
Nanying Yang ◽  
P. G. Schunemann ◽  
S. D. Setzler ◽  
...  

ABSTRACTBulk crystals of CdGeAs2 have been characterized using photoluminescence (PL), optical absorption, Hall effect, and electron paramagnetic resonance (EPR) techniques. An absorption band near 5.5 microns at room temperature is observed in all of the p-type samples we have studied. A correlation between the magnitude of this optical absorption and the excess hole concentration at room temperature is established. Also, an EPR signal is found to correlate with the strength of this absorption band. PL data are consistent with an increased concentration of shallow acceptors being present in high-absorption samples. From the EPR data, we suggest that a model for the paramagnetic defect associated with the absorption at 5.5 microns may be an acceptor on an anion site.


1995 ◽  
Vol 415 ◽  
Author(s):  
Baolin Zhang ◽  
Yixin Jin ◽  
Tianming Zhou ◽  
Hong Jiang ◽  
Yongqiang Ning ◽  
...  

ABSTRACTGaInAsSb/GaSb heterostructures have been grown by metalorganic chemical vapor deposition (MOCVD). The optical properties were characterized using low temperature(71K) photoluminescence(PL) and infrared transmission spectroscopy. The FWHM of the typical PL spectrum peaked at 2.3μm is 30meV. Hall measurement results for undoped GaInAsSb layers are presented showing a p-type background and low hole concentration of 6.5 × 1015cm−3. The room temperature performances of the p-GaInAsSb/n-GaSb photodiodes are reported. Its responsivity spectrum is peaked at 2.2 5μm and cuts off at 1.7μm in the short wavelength and at 2.4μm in the long wavelength, respectively. The room temperature detectivity D* is of 1 × 109cm.Hz1/2.W−2


2014 ◽  
Vol 116 (16) ◽  
pp. 164109 ◽  
Author(s):  
Saif Ullah Awan ◽  
S. K. Hasanain ◽  
D. H. Anjum ◽  
M. S. Awan ◽  
Saqlain A. Shah

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