Ultra-High Speed Solidification and Crystal Growth in Transiently Molten Semiconductor Layers

1983 ◽  
Vol 13 ◽  
Author(s):  
A.G. Cullis
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
High Speed ◽  
Amorphous Solids ◽  
Undercooled Liquid ◽  
Laser Melting ◽  
Amorphous Phases ◽  
Low Viscosity ◽  
Amorphous Si

ABSTRACTThe use of Q-switched laser melting techniques to investigate new rapid solidification phenomena is described. It has been found that Si, Ge, GaP and GaAs can give rise to orientation dependent, kinetically-controlled defect generation processes during fast recrystallization from the melt. Indeed, these materials yield amorphous phases at sufficiently high solidification rates. Ultra-fast pulsed melting permits the study of the basic thermodynamic properties of amorphous solids. It is shown that amorphous Si melts to give a normal, low viscosity, undercooled liquid and that novel explosive crystal growth processes can occur in this low temperature regime.

High speed growth of MAPbBr3 single crystals via low-temperature inverting solubility: enhancement of mobility and trap density for photodetector applications

Nanoscale ◽  
2021 ◽  
Author(s):  
Yunae Cho ◽  
Hye Ri Jung ◽  
Yeon Soo Kim ◽  
Yejin Kim ◽  
Joohee Park ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Low Temperatures ◽  
High Speed ◽  
Single Crystal Growth ◽  
Complete Dissolution ◽  
High Quality ◽  
Optoelectronic Application ◽  
Hybrid Perovskite ◽  
First Time

High-quality CH3NH3PbBr3 hybrid perovskite single crystal growth and outstanding optoelectronic application using the complete dissolution at low temperatures based on low temperature solubility, which has been demonstrated for the first time.

Fundamental Aspects of High Speed Crystal Growth from the Melt

1984 ◽  
Vol 35 ◽  
Author(s):  
A.G. Cullis
Keyword(s):  
Crystal Growth ◽  
High Speed ◽  
Defect Formation ◽  
Solid Phase ◽  
Amorphous Material ◽  
Amorphous Solid ◽  
Growth Behaviour ◽  
Amorphous Si ◽  
Amor Phization ◽  
Melting And Solidification

ABSTRACTAdvances in the study of high speed crystal growth from the melt are reviewed, with special emphasis on the fast melting and solidification of silicon achieved by use of Q-switched laser radiation pulses. Rapid melting of amorphous Si is confirmed to yield a liquid undercooled by several hundred Kelvins and, under suitable conditions, explosive crystal growth processes can occur. The latter involve the self-sustaining propagation of melt bands buried within the initially amorphous material. When the highest quench-rate conditions are established melting of even crystalline Si can yield a final amorphous solid phase. This breakdown in crystal growth is orientation dependent and can give regimes of crystal defect formation when amor-phization does not take place. The processes which characterize this limiting growth behaviour are discussed.

Low-temperature f.e.t. for low-power high-speed logic

1977 ◽  
Vol 13 (6) ◽  
pp. 156 ◽  
Author(s):  
H. Rees ◽  
G.S. Sanghera ◽  
R.A. Warriner
Keyword(s):  
Low Temperature ◽  
Low Power ◽  
High Speed

Integrated low-temperature process for the fabrication of amorphous Si nanoparticles embedded in Al2 O3 for non-volatile memory application

2016 ◽  
Vol 213 (9) ◽  
pp. 2446-2451 ◽  
Author(s):  
Klemens Ilse ◽  
Thomas Schneider ◽  
Johannes Ziegler ◽  
Alexander Sprafke ◽  
Ralf B. Wehrspohn
Keyword(s):  
Low Temperature ◽  
Si Nanoparticles ◽  
Non Volatile Memory ◽  
Amorphous Si ◽  
Volatile Memory ◽  
Low Temperature Process

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

scholarly journals Internal face finishing for a cooling channel using a fluid containing free abrasive grains

2021 ◽  
Author(s):  
Mitsugu Yamaguchi ◽  
Tatsuaki Furumoto ◽  
Shuuji Inagaki ◽  
Masao Tsuji ◽  
Yoshiki Ochiai ◽  
...  
Keyword(s):  
High Speed ◽  
Flow Behavior ◽  
Flow Simulation ◽  
Cooling Channel ◽  
H13 Steel ◽  
Channel Diameter ◽  
Abrasive Grains ◽  
Low Viscosity ◽  
Short Period ◽  
Internal Pressures

AbstractIn die-casting and injection molding, a conformal cooling channel is applied inside the dies and molds to reduce the cycle time. When the internal face of the channel is rough, both cooling performance and tool life are negatively affected. Many methods for finishing the internal face of such channels have been proposed. However, the effects of the channel diameter on the flow of a low-viscosity finishing media and its finishing characteristics for H13 steel have not yet been reported in the literature. This study addresses these deficiencies through the following: the fluid flow in a channel was computationally simulated; the flow behavior of abrasive grains was observed using a high-speed camera; and the internal face of the channel was finished using the flow of a fluid containing abrasive grains. The flow velocity of the fluid with the abrasive grains increases as the channel diameter decreases, and the velocity gradient is low throughout the channel. This enables reduction in the surface roughness for a short period and ensures uniform finishing in the central region of the channel; however, over polishing occurs owing to the centrifugal force generated in the entrance region, which causes the form accuracy of the channel to partially deteriorate. The outcomes of this study demonstrate that the observational finding for the finishing process is consistent with the flow simulation results. The flow simulation can be instrumental in designing channel diameters and internal pressures to ensure efficient and uniform finishing for such channels.

Low-temperature heat capacity and thermodynamic properties of endo-Tricyclo[5.2.1.02,6]decane

2003 ◽  
Vol 35 (12) ◽  
pp. 1897-1903 ◽  
Author(s):  
Li-Guo Kong ◽  
Zhi-Cheng Tan ◽  
Jie Xu ◽  
Shuang-He Meng ◽  
Xin-He Bao
Keyword(s):  
Heat Capacity ◽  
Low Temperature ◽  
Thermodynamic Properties ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity
Sign in / Sign up

Export Citation Format

Share Document