scholarly journals Thin Al 1− x Ga x As 0.56 Sb 0.44 diodes with extremely weak temperature dependence of avalanche breakdown

2017 ◽  
Vol 4 (5) ◽  
pp. 170071 ◽  
Author(s):  
Xinxin Zhou ◽  
Chee Hing Tan ◽  
Shiyong Zhang ◽  
Manuel Moreno ◽  
Shiyu Xie ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Breakdown Voltage ◽  
Experimental Studies ◽  
Temperature Stability ◽  
Operating Conditions ◽  
Avalanche Breakdown ◽  
Avalanche Gain ◽  
Weak Temperature Dependence ◽  
Inp Substrates ◽  
Tunnelling Current

When using avalanche photodiodes (APDs) in applications, temperature dependence of avalanche breakdown voltage is one of the performance parameters to be considered. Hence, novel materials developed for APDs require dedicated experimental studies. We have carried out such a study on thin Al 1– x Ga x As 0.56 Sb 0.44 p–i–n diode wafers (Ga composition from 0 to 0.15), plus measurements of avalanche gain and dark current. Based on data obtained from 77 to 297 K, the alloys Al 1− x Ga x As 0.56 Sb 0.44 exhibited weak temperature dependence of avalanche gain and breakdown voltage, with temperature coefficient approximately 0.86–1.08 mV K −1 , among the lowest values reported for a number of semiconductor materials. Considering no significant tunnelling current was observed at room temperature at typical operating conditions, the alloys Al 1− x Ga x As 0.56 Sb 0.44 (Ga from 0 to 0.15) are suitable for InP substrates-based APDs that require excellent temperature stability without high tunnelling current.

Positive Temperature Coefficient of Avalanche Breakdown Observed in a-Plane 6H-SiC Photodiodes

2009 ◽  
Vol 615-617 ◽  
pp. 865-868
Author(s):  
Stanislav I. Soloviev ◽  
Alexey V. Vert ◽  
Jody Fronheiser ◽  
Peter M. Sandvik
Keyword(s):  
Optical Properties ◽  
Temperature Dependence ◽  
Temperature Coefficient ◽  
Breakdown Voltage ◽  
Avalanche Photodiodes ◽  
Positive Temperature Coefficient ◽  
Avalanche Breakdown ◽  
Positive Temperature ◽  
Electrical And Optical Properties ◽  
Positive Angle

In this work, avalanche photodiodes (APDs) were fabricated using a-plane 6H- and 4H-SiC materials to investigate their electrical and optical properties. Temperature dependence of avalanche breakdown was measured. The diode structures were fabricated with positive angle beveling and oxide passivation to ensure a uniform breakdown across the device area. Despite the apparent presence of micro-plasmas, we observed that the breakdown voltage of a-plane 6H-SiC APDs increased with temperature suggesting a positive temperature coefficient.

scholarly journals Temperature Dependence Study of Mesa-Type InGaAs/InAlAs Avalanche Photodiode Characteristics

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Jack Jia-Sheng Huang ◽  
H. S. Chang ◽  
Yu-Heng Jan ◽  
C. J. Ni ◽  
H. S. Chen ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Breakdown Voltage ◽  
Dark Current ◽  
High Speed ◽  
Impact Ionization ◽  
Low Noise ◽  
Bandgap Energy ◽  
Avalanche Breakdown ◽  
Recombination Mechanism ◽  
Avalanche Breakdown Voltage

Avalanche photodiodes (APDs) are key optical receivers due to their performance advantages of high speed, high sensitivity, and low noise. The most critical device parameters of APD include the avalanche breakdown voltage and dark current. In this work, we study the temperature dependence of the breakdown voltage and dark current of the mesa-type APD over a wide temperature range of 20–145°C. We institute an empirical model based on impact ionization processes to account for the experimental data. It is shown that highly stable breakdown characteristics of mesa-type APD can be attained with the optimization of the multiplication layer design. We have achieved excellent stability of avalanche breakdown voltage with a temperature coefficient of 0.017 V/°C. The temperature dependence of dark current is attributed to generation-recombination mechanism. The bandgap energy is estimated to be about 0.71 eV based on the temperature variation of dark current, in good agreement with the value for InGaAs.

Studies on the Temperature Stability of Pure and Doped Triglycine Sulphate Crystals Using TGA/DTA

2020 ◽  
Vol 10 (3) ◽  
pp. 206-212
Author(s):  
Vijeesh Padmanabhan ◽  
Maneesha P. Madhu ◽  
Supriya M. Hariharan
Keyword(s):  
Thermal Analysis ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Temperature Stability ◽  
Bandgap Energy ◽  
Dsc Analysis ◽  
Slow Cooling ◽  
As Doping ◽  
Similar Dependence ◽  
Temperature Ranges

Aim: To study the temperature stability of TGS doped with ZnSO4, CdCl2, BaCl2, and compare it with that of pure TGS. Objectives: Synthesizing pure and doped TGS and studying their temperature dependence using TGA, DTA, and DSC analysis. Methods: Slow cooling solution growth was used to grow single crystals of pure and doped TGS. The TGA, DTA and DSC analysis was conducted for determining the temperature stability. Results: The thermal analysis of pure and doped TGS shows that the doped samples show a similar dependence on temperature as pure TGS. The temperature of decomposition of pure and doped samples (BTGS, ZTGS, CdTGS) was 226.60°C, 228.38°C, 229.13°C, and 239.13°C respectively. The melting onset of these samples was 214.51°C, 216.04°C, 217.69°C and 216.04°C respectively. Conclusion: The study shows that doping TGS with the above three described materials did not alter their temperature stability considerably. It is a good result as doping TGS, for varying its characteristics like absorbance, reflectance, bandgap energy, etc., which did not alter its temperature stability. Therefore, TGS doped with the above three dopants can be used at the same temperature ranges as of pure TGS but with much-improved efficiency.

scholarly journals Ethanol/Gasoline Blends as Alternative Fuel in Last Generation Spark-Ignition Engines: A Review on CO and HC Engine Out Emissions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4034
Author(s):  
Paolo Iodice ◽  
Massimo Cardone
Keyword(s):  
Physicochemical Properties ◽  
Alternative Fuels ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Exhaust Emissions ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Spark Ignition Engines ◽  
The Impact

Among the alternative fuels existing for spark-ignition engines, ethanol is considered worldwide as an important renewable fuel when mixed with pure gasoline because of its favorable physicochemical properties. An in-depth and updated investigation on the issue of CO and HC engine out emissions related to use of ethanol/gasoline fuels in spark-ignition engines is therefore necessary. Starting from our experimental studies on engine out emissions of a last generation spark-ignition engine fueled with ethanol/gasoline fuels, the aim of this new investigation is to offer a complete literature review on the present state of ethanol combustion in last generation spark-ignition engines under real working conditions to clarify the possible change in CO and HC emissions. In the first section of this paper, a comparison between physicochemical properties of ethanol and gasoline is examined to assess the practicability of using ethanol as an alternative fuel for spark-ignition engines and to investigate the effect on engine out emissions and combustion efficiency. In the next section, this article focuses on the impact of ethanol/gasoline fuels on CO and HC formation. Many studies related to combustion characteristics and exhaust emissions in spark-ignition engines fueled with ethanol/gasoline fuels are thus discussed in detail. Most of these experimental investigations conclude that the addition of ethanol with gasoline fuel mixtures can really decrease the CO and HC exhaust emissions of last generation spark-ignition engines in several operating conditions.

Understanding the superior temperature stability of iridium light-emitting electrochemical cells

2017 ◽  
Vol 4 (4) ◽  
pp. 657-664 ◽  
Author(s):  
Melanie H. Bowler ◽  
Tianle Guo ◽  
Lyndon D. Bastatas ◽  
Matthew D. Moore ◽  
Anton V. Malko ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Temperature Stability ◽  
Electrochemical Cells ◽  
Light Emitting

The temperature dependence of iridium and ruthenium devices are studied, and fundamental assumptions governing their emission are challenged.

Numerical Modeling and Experimental Studies of the Operational Parameters of the Earth-To-Air Heat Exchanger of the Geothermal Ventilation System

2021 ◽  
Vol 23 ◽  
pp. 42-64
Author(s):  
Boris Basok ◽  
Ihor Bozhko ◽  
Maryna Novitska ◽  
Aleksandr Nedbailo ◽  
Myroslav Tkachenko
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Ventilation System ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Operational Parameters ◽  
Cross Sectional ◽  
Distinctive Features ◽  
Sectional Shape ◽  
Experimental Bench

This article is devoted to the analysis of the heat engineering characteristics of the operation of an Earth-to-Air Heat Exchanger, EAHE, with a circular cross-sectional shape, which is a component of the geothermal ventilation system. The authors analyzed literature sources devoted to the research of heat exchangers of the soil-air type of various designs and for working conditions in various soils. Much attention is paid to the issues of modeling the operation of such heat exchangers and the distinctive features of each of these models. Also important are the results of experimental studies carried out on our own experimental bench and with the help of which the numerical model was validated. The results of these studies are the basis for the development of a method for determining the optimal diameter of an EAHE under operating conditions for soil in Kyiv, Ukraine.

On the Breakdown Voltage Temperature Dependence of High-Voltage Power Diode Passivated with Diamond-Like Carbon

2021 ◽  
Author(s):  
Luigi Balestra ◽  
Susanna Reggiani ◽  
Antonio Gnudi ◽  
Elena Gnani ◽  
Jagoda Dobrzynska ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Diamond Like Carbon ◽  
Power Diode

scholarly journals Temperature Dependence of Mechanical, Electrical Properties and Crystal Structure of Polyethylene Blends for Cable Insulation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1922 ◽  
Author(s):  
Lunzhi Li ◽  
Lisheng Zhong ◽  
Kai Zhang ◽  
Jinghui Gao ◽  
Man Xu
Keyword(s):  
High Temperature ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
Breakdown Strength ◽  
Temperature Stability ◽  
Xrd Analysis ◽  
Insulation Material ◽  
Cable Insulation ◽  
Polyethylene Blends

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.

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