scholarly journals Enhanced optical properties of chemical vapor deposited single crystal diamond by low-pressure/high-temperature annealing

2008 ◽  
Vol 105 (46) ◽  
pp. 17620-17625 ◽  
Author(s):  
Yu-fei Meng ◽  
Chih-shiue Yan ◽  
Joseph Lai ◽  
Szczesny Krasnicki ◽  
Haiyun Shu ◽  
...  

Single crystal diamond produced by chemical vapor deposition (CVD) at very high growth rates (up to 150 μm/h) has been successfully annealed without graphitization at temperatures up to 2200 °C and pressures <300 torr. Crystals were annealed in a hydrogen environment by using microwave plasma techniques for periods of time ranging from a fraction of minute to a few hours. This low-pressure/high-temperature (LPHT) annealing enhances the optical properties of this high-growth rate CVD single crystal diamond. Significant decreases are observed in UV, visible, and infrared absorption and photoluminescence spectra. The decrease in optical absorption after the LPHT annealing arises from the changes in defect structure associated with hydrogen incorporation during CVD growth. There is a decrease in sharp line spectral features indicating a reduction in nitrogen-vacancy-hydrogen (NVH−) defects. These measurements indicate an increase in relative concentration of nitrogen-vacancy (NV) centers in nitrogen-containing LPHT-annealed diamond as compared with as-grown CVD material. The large overall changes in optical properties and the specific types of alterations in defect structure induced by this facile LPHT processing of high-growth rate single-crystal CVD diamond will be useful in the creation of diamond for a variety of scientific and technological applications.

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Hao Liu ◽  
Jia-jun Li ◽  
Zhen-rui Li ◽  
Kai Xu ◽  
Zheng-jia Chen ◽  
...  

Single crystal diamonds were deposited on high pressure high temperature (HPHT) substrate with high growth rate, up to 18.5 μm/h, by using dual radio-frequency inductive coupled plasma jet. The methane flux was found to influence the growth rate of single crystal diamond. The reason for this might be ascribed to the electron temperature increase, raising the flux of methane, based on the plasma diagnosis results by optical emission spectra (OES). The results of Raman spectroscopy and the X-ray rocking-curve indicated that as-deposited diamonds are of good quality.


2004 ◽  
Vol 13 (4-8) ◽  
pp. 557-560 ◽  
Author(s):  
Oliver A. Williams ◽  
Richard B. Jackman

2013 ◽  
Vol 740-742 ◽  
pp. 65-68 ◽  
Author(s):  
Kazuhiko Kusunoki ◽  
N. Yashiro ◽  
Nobuhiro Okada ◽  
Kouji Moriguchi ◽  
Kazuhito Kamei ◽  
...  

4H-SiC single crystal with 3-inch diameter was grown by top seeded solution growth (TSSG) technique. We used a new convection control member called “Immersion Guide (IG)” which causes the high and homogenous fluid flow in the solution. As a result, we achieved relatively high growth rate and morphological stability


2001 ◽  
Vol 664 ◽  
Author(s):  
A. R. Middya ◽  
U. Weber ◽  
C. Mukherjee ◽  
B. Schroeder

ABSTRACTWe report on ways to develop device quality microcrystalline silicon (μc-Si:H) intrinsic layer with high growth rate by hot-wire chemical vapor deposition (HWCVD). With combine approach of controlling impurities and moderate H-dilution [H2/SiH4 ͌ 2.5], we developed, for the first time, highly photosensitive (103 μc-Si:Hfilms with high growth rate (>1 nm/s); the microstructure of the film is found to be close to amorphous phase (fc ͌ 46 ̻± 5%). The photosensitivity systematically decreases with fc and saturates to 10 for fc> 70%. On application of these materials in non-optimized pin [.proportional]c-Si:H solar cell structure yields 700 mV open-circuit voltage however, surprisingly low fill factor and short circuit current. The importance of reduction of oxygen impurities [O], adequate passivation of grain boundary (GB) as well as presence of inactive GB of (220) orientation to achieve efficient [.proportional]c-Si:H solar cells are discussed.


2016 ◽  
Vol 858 ◽  
pp. 1210-1213 ◽  
Author(s):  
Shota Watanabe ◽  
Masashi Nagaya ◽  
Yukihisa Takeuchi ◽  
Kenta Aoyagi ◽  
S. Harada ◽  
...  

We achieved a high growth rate in solution growth of AlN single crystal by suppressing unintentional precipitations near the surface of solvent and by increasing the equilibrium nitrogen concentration in the solvent. In order to suppress unintentional precipitations, we made the solvent supersaturated just above the surface of the substrate by optimizing the composition of the solvent and the temperature distribution based on thermodynamic numerical analysis. In particular, we focused on interactions between nitrogen or aluminum and solvent elements, leading to the increase of the equilibrium nitrogen concentration. We selected chromium and cobalt due to their high affinity with nitrogen or aluminum. Consequently, we successfuly achieved growth rate as high as 200 μm/h in maximum.


Sign in / Sign up

Export Citation Format

Share Document