scholarly journals Effect of Internal Radiation on Process Parameters in the Global Simulation of Growing Large-Size Bulk β-Ga2O3 Single Crystals with the Czochralski Method

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 763
Author(s):  
Xia Tang ◽  
Botao Liu ◽  
Yue Yu ◽  
Botao Song ◽  
Pengfei Han ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Single Crystal ◽  
Process Parameters ◽  
Czochralski Method ◽  
Surface Radiation ◽  
Czochralski Growth ◽  
Internal Radiation ◽  
System A ◽  
Large Size ◽  
Growth System

As a crystal grows, the temperature distribution of the crystal and melt will change. It is necessary to study the dynamic process of single-crystal growth. Due to the relatively low crystallization rates used in the industrial Czochralski growth system, a steady state is used to compute the temperature distribution and melt flow. A two-dimensional axisymmetric model of the whole Czochralski furnace was established. The dynamic growth process of large-size bulk β-Ga2O3 single crystal using the Czochralski method has been numerically analyzed with the parameter sweep method. In this paper, two cases of internal radiation and no internal radiation were compared to study the effect of radiation on the process parameters. The temperature distribution of the furnace, the temperature field, and the flow field of the melt was calculated. The temperature, the temperature gradient of the crystal, the temperature at the bottom of the crucible, and the heater power were studied for the crystals grown in the two cases of radiation. The results obtained in this study clearly show that the loss calculated by including the internal radiation is higher compared to that including the surface radiation.

scholarly journals The Effect of the Crucible on the Temperature Distribution for the Growth of a Large Size AlN Single Crystal

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 54
Author(s):  
Yue Yu ◽  
Botao Liu ◽  
Xia Tang ◽  
Botao Song ◽  
Pengfei Han ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Single Crystal ◽  
Crystal Size ◽  
Tantalum Carbide ◽  
Crucible Wall ◽  
Specific Effects ◽  
Large Size ◽  
Axial Temperature ◽  
Growth System

The appropriate distribution of temperature in the growth system is critical for obtaining a large size high quality aluminum nitride (AlN) single crystal by the physical vapor transport (PVT) method. As the crystal size increases, the influence of the crucible on the temperature distribution inside the growth chamber becomes greater. In order to optimize the field of temperature and study the specific effects of various parts of the crucible on the large size AlN single crystal growth system, this study carried out a series of numerical simulations of the temperature field of two crucibles of different materials and put forward the concept of a composite crucible, which combines different materials in the crucible parts. Four composite crucible models were established with different proportions and positions of tantalum carbide (TaC) parts and graphite parts in the crucible. Calculations reveal that different parts of the crucible have different effects on the internal temperature distribution. The axial temperature gradient at the crystal was mainly governed by the crucible wall, whereas the temperature gradient was determined by the integrated effect of the crucible lid and the crucible wall in the radial direction. One type of composite crucible was chosen to minimize the thermal stress in grown AlN crystal, which is applicable to the growth of large sized AlN crystals in the future; it can also be used to grow AlN single crystals at present as well.

InSb Czochralski Growth Single Crystals for InGaSb Substrates

2014 ◽  
Vol 1616 ◽  
Author(s):  
J. E. Flores Mena ◽  
R. Castillo Ojeda ◽  
J. Díaz Reyes
Keyword(s):  
Low Cost ◽  
Electronic Devices ◽  
Czochralski Method ◽  
Liquid Nitrogen Temperature ◽  
Longitudinal Optical ◽  
Czochralski Growth ◽  
Etch Pit ◽  
Growth System ◽  
Radiation Sensors ◽  
Made In

ABSTRACTThe massive crystal growth of single crystal semiconductors materials has been of fundamental importance for the actual electronic devices industry. As a consequence of this one, we can obtain easily a large variety of low cost devices almost as made ones of silicon. Nowadays, the III-V semiconductors compounds and their alloys have been proved to be very important because of their optical properties and applications. It is the case of the elements In, Ga, As, Sb, which can be utilized for the fabrication of radiation sensors. In this work we present the results obtained from the ingots grown by the Czochralski method, using a growth system made in home. These results include anisotropic chemical attacks in order to reveal the crystallographic orientation and the possible polycrystallinity. Isotropic chemical attacks were made to evaluate the etch pit density. Metallographic pictures of the chemical attacks are presented in this work. Among the results of these measurements, the best samples presented in this work showed mobilities of 62.000 cm2/V*s at room temperature and 99.000 cm2/V*s at liquid nitrogen temperature. Typical pit density was 10,000/cm2. The Raman spectra present two dominant peaks associated at Transversal Optical (TO)- and Longitudinal Optical (LO)-InSb, the first vibrational mode is dominant due to the crystalline direction of the ingots and second one is associated to high defects density.

Optical, Structural and Spectroscopic Characterization of ZnS Nanocrystals Embedded in KBr Single Crystal Matrix Grown by Czochralski Method

2021 ◽  
Vol 406 ◽  
pp. 274-284
Author(s):  
Soria Zeroual ◽  
Mohammed Sadok Mahboub ◽  
Ghani Rihia ◽  
Mourad Mimouni ◽  
Ghougali Mebrouk ◽  
...  
Keyword(s):  
Single Crystal ◽  
Absorption Edge ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Czochralski Method ◽  
Spectroscopic Characterization ◽  
Czochralski Growth ◽  
X Ray Diffraction ◽  
Crystal Matrix ◽  
Zns Nanocrystals

ZnS nanocrystals were embedded in a KBr single crystal matrix using the Czochralski growth technique. The X-ray diffraction, FT-IR and optical spectroscopy revealed the incorporation of ZnS nanocrystals. A blue shift of the absorption edge of the obtained samples has been observed, indicating the quantum confinement effect. The optical band-gap is estimated to be about 4.67 eV. Two excitonic peaks appeared at 300.4 nm and 271 nm. The average nanocrystal size was derived from the optical spectra. Annealing led to a shift in the absorption edge towards longer wavelengths and an increasing of the emissions intensity. Raman lines of the nanoparticles are broader and frequency-shifted compared to those of the bulk crystals. These results show that KBr is a good matrix-host of ZnS nanocrystals, and that the elaborated samples can be used for important technological applications.

Analysis to Reduce Thermal Stress in Oxide Single Crystal During Czochralski Growth

2004 ◽  
Author(s):  
Shigeki Hirasawa ◽  
Hiroyuki Ishibashi ◽  
Kazuhisa Kurashige ◽  
Akihiro Gunji
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Temperature Distribution ◽  
Thermal Radiation ◽  
Single Crystal ◽  
Radiation Heat Transfer ◽  
Heat Transfer Analysis ◽  
Czochralski Growth ◽  
Radiation Heat ◽  
Radial Temperature

Temperature distributions and thermal stress distributions in a semi-transparent GSO crystal during Czochralski (CZ) single crystal growth were numerically investigated by thermal radiation heat transfer analysis and anisotropy stress analysis. As GSO has special optical properties, such as semi-transparency at a wavelength shorter than 4.5 μm, thermal radiation heat transfer was calculated by the Monte Carlo method. These calculations showed that thermal stress is caused by the radial temperature distribution on the outside of the upper part of the crystal. To reduce this temperature distribution, the following three manufacturing conditions were found to be effective: use a sharp taper angle of the crystal, install a lid to the top of the insulator, and install a ring around the tapered part of the crystal.

Effect of New Thermal Insulation to the Growth of LiNbO3 Single Crystal by Czochralski Method

2013 ◽  
Vol 701 ◽  
pp. 108-112
Author(s):  
W.H.A. Kamaruddin ◽  
Hamdan Hadi Kusuma ◽  
Zuhairi Ibrahim
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Thermal Insulation ◽  
Growth Process ◽  
Thermal Environment ◽  
Czochralski Method ◽  
Control Power ◽  
Air Atmosphere ◽  
Growth System ◽  
Hot Zone

Single crystal of LiNbO3has been successfully grown by the Czochralski method in an air atmosphere with a r.f heating crystal growth system namely Automatic Diameter Control Crystal Growth System (ADC-CGS). This paper reports on the effect of new thermal insulation on the growth process of LiNbO3single crystal. The effect of hot zone thermal insulation design was investigated. The conditions required to grow high quality LiNbO3single crystals are described. A set of crystal growth processes were conducted with the rotation rate of the seed at 15 rpm and the pulling rate at 2.0 mm/hr kept constant. All of the runs were grown along <104> orientation. To control the diameter of the crystal, we have to alter the thermal environment inside the hot zone. In other words, during the crystal growth we have to increase the control power to get smaller diameter and decrease the control power to get larger diameter.

Luminescence properties of large-size Li2MoO4 single crystal grown by Czochralski method

2021 ◽  
pp. 126022
Author(s):  
Xin Chen ◽  
Peng Chen ◽  
Linwen Jiang ◽  
Yan Zhao ◽  
Yaping Chen ◽  
...  
Keyword(s):  
Single Crystal ◽  
Czochralski Method ◽  
Luminescence Properties ◽  
Large Size

Growth and Characterization of Titanium Doped Lithium Niobate Single Crystal Using Czochralski Technique

2017 ◽  
Vol 268 ◽  
pp. 205-209
Author(s):  
K.Z. Hashim ◽  
Md Supar Rohani ◽  
Wan Hairul Anuar Kamaruddin
Keyword(s):  
Lithium Niobate ◽  
Single Crystal ◽  
Growth Parameters ◽  
Visible Region ◽  
Fundamental Absorption Edge ◽  
Czochralski Method ◽  
Effective Control ◽  
Vis Spectroscopy ◽  
Growth System ◽  
The Right

A successful growth of the titanium-doped lithium niobate (Ti: LiNbO3) single crystal by Czochralski method is reported. By preserving an effective control of growth parameters such as maintaining accurate temperature gradient by controlling its output power and growth rate as well as wisely choosing the right pulling rate and speed rotation, the Ti:LiNbO3 single crystal successfully produced using Automatic Diameter Control-Crystal Growth System (ADC-CGS). The structural and optical analyses have been done by using X-ray Diffractometer (XRD), Differential Thermal Analyzer (DTA) and Ultraviolet-Visible (UV-Vis) spectroscopy. The crystallinity of the sample has been confirmed using XRD and DTA has been used to determine the crystal nature of the sample. The position of fundamental absorption edge was recorded via transmission spectra in UV and visible region.

scholarly journals Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3–Sc2O3–Y2O3

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Christian Kränkel ◽  
Anastasia Uvarova ◽  
Émile Haurat ◽  
Lena Hülshoff ◽  
Mario Brützam ◽  
...  
Keyword(s):  
Ternary System ◽  
Czochralski Method ◽  
Optical Quality ◽  
Czochralski Growth ◽  
High Optical Quality ◽  
Melting Temperatures ◽  
Large Size ◽  
Host Materials ◽  
Thermal Investigations ◽  
First Time

Cubic rare-earth sesquioxide crystals are strongly demanded host materials for high power lasers, but due to their high melting points investigations on their thermodynamics and the growth of large-size crystals of high optical quality remain a challenge. Detailed thermal investigations of the ternary system Lu2O3–Sc2O3–Y2O3 revealing a large range of compositions with melting temperatures below 2200°C and a minimum of 2053°C for the composition (Sc0.45Y0.55)2O3 are presented. These reduced temperatures enable for the first time the growth of high optical quality mixed sesquioxide crystals with disordered structure by the conventional Czochralski method from iridium crucibles. An (Er0.07Sc0.50Y0.43)2O3 crystal is successfully grown and characterized with respect to its crystallographic properties as well as its composition, thermal conductivity and optical absorption in the 1 µm range.

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