Temperature analysis and effects on SQW PbSe/PbSrSe energy levels, modal gain, and current density

2012 ◽  
Author(s):  
M. Khodr
2021 ◽  
Author(s):  
Ravi Ranjan ◽  
Prakash Pareek ◽  
Mukul Kumar Das ◽  
Saurabh Kumar Pandey

Abstract In this work, a theoretical model is developed for n-p-n mid-infrared transistor laser (TL) with strain-balanced Ge0.85Sn0.15 multiple quantum well (MQW) structure in the base. Variation of optical confinement factor, modal gain and threshold current density have been rigorously investigated for different number of QWs (N) in MQW structure. The result shows that overall optical confinement factor and modal gain increase with N. The frequency response of MQWTL for common base (CB) configuration is estimated from small signal relationship between the photon density and emitter current density by solving laser rate equation and continuity equation considering the virtual states as a conversion mechanism. Increment of N causes modulation bandwidth to initially increase and then decreases with N, which reveals a shifting of device nature for higher values of N. The results also suggest that on judicious selection of N, the proposed device can become a viable monolithic light source.


2021 ◽  
Vol 101 (3) ◽  
pp. 31-41
Author(s):  
N. Stechishina ◽  
◽  
M. Stechishin ◽  
A. Martynyuk ◽  
N. Lukianyuk ◽  
...  

One of the modern and effective methods of hardening metals is nitriding in a glow discharge in ammonia or in an anhydrous medium (nitrogen + argon) - BATR. This paper presents the results of experimental studies comparing the results of tribological and physicochemical properties of hardened surfaces obtained by nitriding with autonomous and interconnected BATR modes. The complex of traditionally fixed values of operating parameters (temperature, composition of the gas mixture, pressure and saturation time) without taking into account energy characteristics (voltage, current density and specific discharge power) significantly reduces the technological capabilities of BATR to achieve the necessary physicochemical properties of metal surfaces specified by conditions exploitation. Taking into account the energy characteristics of BATR, a significant reduction in the energy consumption of the nitriding process is achieved. The energy levels of the main subprocesses are significantly different: the formation of nitrides occurs at low energies, surface sputtering occurs at high voltage values, and nitrogen diffusion occurs at increased current density values. In cases where the energy of the flow is insufficient, either a glow discharge may not occur at all, or with a lack of voltage, the nitride ball on the surface is not sprayed and it acts as a barrier that prevents the diffusion process into the inner layers of the metal, which leads to low physicochemical and, correspondingly, tribological indicators of nitrided balls. The quantitative ratio between them and the required operational properties of the metal, respectively, can be achieved only through an independent combination of the energy and operating characteristics of BATR


2019 ◽  
Vol 34 (10) ◽  
pp. 1950056 ◽  
Author(s):  
M. A. Hun ◽  
N. Candemir

In this paper, a relativistic behavior of spin-zero bosons is studied in a chiral cosmic string space–time. The Duffin–Kemmer–Petiau (DKP) equation and DKP oscillator are written in this curved space–time and are solved by using an appropriate ansatz and the Nikiforov–Uvarov method, respectively. The influences of the topology of this space–time on the DKP spinor and energy levels and current density are also discussed in detail.


2016 ◽  
Vol 4 (21) ◽  
pp. 8291-8297 ◽  
Author(s):  
Dongfeng Dang ◽  
Pei Zhou ◽  
Linrui Duan ◽  
Xichang Bao ◽  
Renqiang Yang ◽  
...  

Good light harvesting properties and matched energy levels as well as enhanced Jsc value and high Voc value in solar cells were achieved simultaneously by construction of the D–A–π–A type regular terpolymers of PIDT-DTQ-TT, finally leading to the maximum PCE value of 6.63% in PSCs.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
A. R. Kalaiarasi ◽  
T. Deepa ◽  
S. Angalaeswari ◽  
D. Subbulekshmi ◽  
Raja Kathiravan

This work is focused on design and simulation of microelectromechanical system (MEMS)/nanoelectromechanical system (NEMS) rotational devices such as micro/nanothermal rotary actuator and micro/nanogear. MEMS/NEMS technologies have allowed the development of advanced miniaturized rotational devices. MEMS/NEMS-based thermal actuator is a scaled version of movable device which will produce amplified motion when it is subjected to thermal forces. One of the applications of such thermal micro/nanoactuator is integrating it into micro/nanomotor that makes a thermal actuated micro/nanomotor. In this work, design and simulation of micro/nanothermal rotary actuator are done using MEMS/NEMS technology. Stress, current density, and temperature analysis are done for microthermal rotary actuator. The performance of the device is observed by varying the dimensions and materials such as silicon and polysilicon. Stress analysis is used to calculate the yield strength of the material. Current density is used to calculate the safer limit of the material. Temperature analysis is used to calculate the melting point of the material. Also, in this work, design and simulation of microgear have been done. Micro/nanogears are devices that can be used to improve motion performance. The essential is that it transmits rotational motion to a different axis.


2019 ◽  
Vol 127 (12) ◽  
pp. 963 ◽  
Author(s):  
Л.Я. Карачинский ◽  
И.И. Новиков ◽  
А.В. Бабичев ◽  
А.Г. Гладышев ◽  
Е.С. Колодезный ◽  
...  

An active region design based on the InGaAs/InGaAlAs superlattice for laser diodes of 1535-1565 nm spectral range was proposed and experimentally realized. It has been shown that the use of active region design based on superlattice allows increasing the modal gain at equal values of the pump current density in comparison with a common used active-region design based on a set of InGaAs quantum wells.


Author(s):  
Mykola Skyba ◽  
Myroslav Stechyshyn ◽  
Mykola Lukianiuk ◽  
Volodymyr Kurskoi ◽  
Nataliia Mashovets ◽  
...  

The influence of regime (temperature, composition of gas mixture and its pressure) and energy characteristics (voltage, current density, specific discharge power) at hydrogen-free-nitriding in a glow discharge (HFNGD) on the structure, phase composition of nitrided layers is investigated. It is shown that due to the combination of regime and energy parameters of HFNGD it is possible to achieve physical and chemical indicators of nitrided layers set by operating conditions. The set of traditionally fixed values of regime parameters (temperature, gas mixture connection, pressure and saturation time) without taking into account energy characteristics (voltage, current density and specific discharge power) significantly reduces the technological capabilities of HFNGD. With controlled regulation of the energy characteristics of HFNGD, a significant reduction in the energy consumption of the nitriding process is achieved. It is established that the energy levels of the main subprocesses differ significantly: the formation of nitrides occurs at low energies, surface sputtering is realized at high voltage values, and nitrogen diffusion occurs at high current densities. In cases where the flow energy is insufficient, either a glow discharge may not occur at all, or at insufficient stress the nitride layer on the surface is not sprayed and it acts as a barrier that prevents the diffusion process into the inner layers of the metal, leading to low physicochemical indicators of nitrided layers. The priority in the formation of one or another phase (, , u, ), the quantitative ratio between them and the required performance properties of the metal, respectively, can be achieved only through an independent combination of energy and regime characteristics of HFNGD.


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