scholarly journals Regulation of Substrate-Target Distance on the Microstructural, Optical and Electrical Properties of CdTe Films by Magnetron Sputtering

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2496 ◽  
Author(s):  
Peng Gu ◽  
Xinghua Zhu ◽  
Haihua Wu ◽  
Dingyu Yang

Cadmium telluride (CdTe) films were deposited on glass substrates by direct current (DC) magnetron sputtering, and the effect of substrate-target distance (Dts) on properties of the CdTe films was investigated by observations of X-ray diffraction (XRD) patterns, atomic force microscopy (AFM), UV-VIS spectra, optical microscopy, and the Hall-effect measurement system. XRD analysis indicated that all samples exhibited a preferred orientation along the (111) plane, corresponding to the zinc blende structure, and films prepared using Dts of 4 cm demonstrated better crystallinity than the others. AFM studies revealed that surface morphologies of the CdTe films were strongly dependent on Dts, and revealed a large average grain size of 35.25 nm and a high root mean square (RMS) roughness value of 9.66 nm for films fabricated using Dts of 4 cm. UV-VIS spectra suggested the energy band gap (Eg) initially decreased from 1.5 to 1.45 eV, then increased to 1.68 eV as Dts increased from 3.5 to 5 cm. The Hall-effect measurement system revealed that CdTe films prepared with a Dts of 4 cm exhibited optimal electrical properties, and the resistivity, carrier mobility, and carrier concentration were determined to be 2.3 × 105 Ω∙cm, 6.41 cm2∙V−1∙S−1, and 4.22 × 1012 cm−3, respectively.

2013 ◽  
Vol 1511 ◽  
Author(s):  
Isil Berkun ◽  
Shannon N. Demlow ◽  
Nutthamon Suwanmonkha ◽  
Timothy P. Hogan ◽  
Timothy A. Grotjohn

ABSTRACTA temperature dependent Hall Effect measurement system with software based data acquisition and control was built and tested. Transport measurements are shown for boron-doped single crystal diamond (SCD) films deposited in a microwave plasma-assisted chemical vapor deposition (MPCVD) reactor. The influence of Ohmic contacts and temperature control accuracy are studied. For a temperature range of 300K-700K IV curves, Hall mobilities and carrier concentrations are presented.


2009 ◽  
Vol 421-422 ◽  
pp. 463-466 ◽  
Author(s):  
Jian Yong Li ◽  
Takeshi Ohgaki ◽  
Ryota Matsuoka ◽  
Hideyo Okushi ◽  
Naoki Ohashi

In this study, we successfully fabricated the Schottky junctions consisting of Pt electrode and high concentration Nb-doped (0.5 wt%) SrTiO3 (001) single crystal by sputtering process. The carrier concentrations of Nb-0.5wt%-doped SrTiO3 were determined as 1020 /cm3 order by Hall effect measurement. The electrical properties of junctions were investigated by measuring their current-voltage (I-V), capacitance-voltage (C-V) characteristics at temperature range from 80K to 400K. The hysteresis feature was observed that indicating the alteration of barrier height in junctions especially at lower temperature. The donor concentration and built-in potentials calculated from C-2-V data showed large discrepancy from Hall effect measurement indicating that the junctions deviate from the ideal Schottky diode model.


2014 ◽  
Vol 609-610 ◽  
pp. 113-117
Author(s):  
Ya Juan Sun ◽  
Wan Xing Wang

Since ZnO is a wide band gap (3.37 eV) semiconductor with a large exitonic binding energy (60 meV), it has been considered as a candidate for various applications, such as ultraviolet (UV) light emitting diodes and laser diodes. For the applications of ZnO-based optoelectronic devices, it is necessary to produce n and p type ZnO films with the high quality. Since ZnO is naturally n-type semiconductor material due to intrinsic defects, such as oxygen vacancies, zinc interstitials, etc., it is easy to produce n-type ZnO with high quality. However, it is difficult to produce low-resistive and stable p-type ZnO due to its asymmetric doping limitations and the self-compensation effects of the intrinsic defects. According to the theoretical studies, p-type ZnO can be realized using group-V dopants substituting for O, such as N, P and As. Among them, N has been suggested to be an effective acceptor dopant candidate to achieve p-type ZnO, because that nitrogen has a much smaller ionic size than P and As and the energy level of substitutional NOis lower than that of substitutional POand AsO.Transparent p-type ZnO: N thin films have been fabricated using the pulsed laser deposition method at deposition temperatures 800 °C under the O2and N2mixing pressure 6Pa. N-doped ZnO films were deposited on sapphire substrate using metallic zinc (99.999%) as target. The structural, optical and electrical properties of the films were examined by XRD, UV-visit spectra and Hall effect measurement. We found that thin film contain the hexagonal ZnO structure. The Hall effect measurement revealed that the carrier concentration is 5.84×10181/ cm3, and Hall mobility is 0.26 cm2/Vs, electrical resistivity is 4.12ohm-cm. Film thickness is 180nm. Besides, Visible light transmittance is more than 80%, and calculative band-gap is 3.1 eV, which is lower than ZnO.


2021 ◽  
Vol 129 (1) ◽  
pp. 015102
Author(s):  
Ryo Ogawa ◽  
Tatsunori Okada ◽  
Hideyuki Takahashi ◽  
Fuyuki Nabeshima ◽  
Atsutaka Maeda

2009 ◽  
Vol 34 (4) ◽  
pp. 755-757 ◽  
Author(s):  
K. Yamada ◽  
T. Yamaguchi ◽  
N. Kokubo ◽  
B. Shinokazi ◽  
K. Yano ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document