A Study of Free- and Bound-Exciton Recombination in Device Quality Diamond

1995 ◽  
Vol 416 ◽  
Author(s):  
S. J. Sharp ◽  
A. T. Collins
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Temperature Dependence ◽  
High Purity ◽  
Vapour Deposition ◽  
Synthetic Diamond ◽  
Free Exciton ◽  
Chemical Vapour ◽  
High Pressure High Temperature ◽  
Exciton Recombination

ABSTRACTA cathodoluminescence (CL) study of free- and bound-exciton recombination in high purity high pressure high temperature (HPHT) synthetic diamond is presented, including temperature dependence measurements of the free-exciton intensity and luminescence decaytime. The results are compared with those from device quality diamond produced using the chemical vapour deposition (CVD) process.

scholarly journals High pressure synthesis of BN and BCN crystals and their functionalization

2014 ◽  
Vol 70 (a1) ◽  
pp. C751-C751
Author(s):  
Takashi Taniguchi
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
High Purity ◽  
Chemical Vapour ◽  
Attractive Potential ◽  
Luminescence Spectra ◽  
Hard Material ◽  
High Temperature Annealing ◽  
Electrical Insulator ◽  
Carbon Impurity

Hexagonal BN (hBN) and cubic BN (cBN) are known as the representative crystal structures of BN. The former is chemically and thermally stable, and has been widely used as an electrical insulator and heat-resistant materials. The latter, which is a high-density phase, is an ultra-hard material second only to diamond. Recently, some progresses in the synthesis of high purity BN crystals were achieved by using Ba-BN as a solvent material at high pressure crystal growth [1]. Band-edge natures (cBN Eg=6.2eV and hBN Eg=6eV) were characterized by their optical properties. The key issue to obtain high purity crystals is to reduce oxygen and carbon contamination in the growth circumstances. It should be emphasized that hBN exhibits attractive potential for deep ultraviolet (DUV) light emitter [2 ] and also superior properties as substrate of graphene devices [3]. In this study, the effect of carbon impurity in BN is investigated. Three types of experimental approaches were carried out; (1) synthesis of high purity hBN single crystals and its characterization with respect to residual carbon, (2) high temperature solid state diffusion of carbon into hBN and its characterization, and (3) high temperature annealing of turbostratic B-C-N(t-BCN) compound under high pressure. t-BCN flakes obtained by chemical vapour deposition process was annealed near 3000C and 2GPa so as to become well crystallized.At annealing near 3000C at 2GPa with graphite, carbon incorporation of 1E21/cm3 in hBN was achieved with exhibiting totally different Cathode Luminescence spectra feature with high purity hBN crystals. Since major carbon contribution may affect the crystal structure of the 2-D layers stacking in hBN system, phase stability of BCN ternary phase will be introduced by the experimental results of high temperature annealing. Furthermore, effect of carbon impurity upon the synthesis of wurtzite BN from highly crystalline hBN via martensitic phase transformation will also be introduced.

scholarly journals Superhard Superconductor Composites Obtained by Sintering of Diamond, c-BN and C60 Powders with Superconductors

2006 ◽  
Vol 61 (12) ◽  
pp. 1541-1546 ◽  
Author(s):  
Gennadi A. Dubitsky ◽  
Vladimir D. Blank ◽  
Sergei G. Buga ◽  
Elena E. Semenova ◽  
Nadejda R. Serebryanaya ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Critical Temperature ◽  
Boron Nitride ◽  
Synthetic Diamond ◽  
Cubic Boron Nitride ◽  
High Pressure High Temperature ◽  
Diamond Powders

Superhard superconducting samples with a critical temperature of TC = 10.5 - 12.6 K were obtained by high-pressure / high-temperature sintering of synthetic diamond powders coated with a niobium film and in 50% - 50% composition with superhard C60 fullerene. Superhard superconductors with TC = 9.3 K were obtained when diamond and molybdenum powders were sintered at a pressure of 7.7 GPa and a temperature of 2173 K. Superconducting samples with TC = 36.1 - 37.5 K have been obtained in the systems diamond-MgB2 and cubic boron nitride-MgB2.

Gemologic and Spectroscopy Properties of Chinese High-Pressure High-Temperature Synthetic Diamond

JOM ◽  
2019 ◽  
Vol 71 (8) ◽  
pp. 2531-2540 ◽  
Author(s):  
Xuemei He ◽  
Mingyue Du ◽  
Yihe Zhang ◽  
Park K. Chu ◽  
Qingfeng Guo
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthetic Diamond ◽  
High Pressure High Temperature

CVD Micron Diamond Powders

2013 ◽  
Vol 797 ◽  
pp. 495-499 ◽  
Author(s):  
T. Zhang ◽  
F.H. Sun ◽  
Bin Shen ◽  
Z.M. Zhang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Silicon Wafer ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Large Area ◽  
Secondary Nucleation ◽  
Diamond Powders ◽  
Hot Filament ◽  
Spin Coater

The conventional diamond powders (< 10 μm) are generally produced from crushing the large-sized diamonds synthesized by high-pressure and high-temperature (HPHT) technique, whereas they have many morphological imperfections. In the present work, the hot filament chemical vapour deposition (HFCVD) technique is employed for synthesizing such diamond powders. A great many of micron diamonds are grown simultaneously but independently onto a large-area substrate. First, the seeds with an appropriate density approximately 1.3×1010 m-2 are dispersed evenly onto a mirror-polished silicon wafer by using a spin coater machine. Afterwards, the regrowth mechanism of seeds is mainly discussed. The results demonstrate that the unwanted spontaneous and secondary nucleation play a determinant role in keeping well in the morphology of crystals and inhibiting the poly-crystals growth.

CVD-Growth of Low-Doped 6H SIC Epitaxial Films

1994 ◽  
Vol 339 ◽  
Author(s):  
O. Kordina ◽  
A. Henry ◽  
C. Hallin ◽  
R. C. Glass ◽  
A. O. Konstantinov ◽  
...  
Keyword(s):  
Vapour Deposition ◽  
Free Exciton ◽  
Chemical Vapour ◽  
Epitaxial Films ◽  
Temperature Growth ◽  
Capacitance Voltage ◽  
Exciton Recombination ◽  
Cvd Growth ◽  
Wall System ◽  
Sic Films

ABSTRACTWe present a method for growing low-doped 6H SiC films using chemical vapour deposition in a hot-wall system. The study discusses the influence of temperature, growth rate and C/Si ratio on the purity of the layers. Furthermore, we make a comparison between methane and propane as carbon source, and investigate the influence of bake-out prior to growth. The films are characterised using low temperature photoluminescence. The relative intensity of the free exciton related luminescence as compared to impurity related bound exciton recombination is discussed in terms of material purity. A capacitance-voltage technique is used to determine the doping concentration.

Ion-exchange properties of High Pressure High Temperature synthetic diamond

2017 ◽  
Vol 75 ◽  
pp. 131-139 ◽  
Author(s):  
Anton Peristyy ◽  
Aleksandra N. Koreshkova ◽  
Brett Paull ◽  
Pavel N. Nesterenko
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Ion Exchange ◽  
Synthetic Diamond ◽  
High Pressure High Temperature ◽  
Exchange Properties
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