scholarly journals Technology CAD (TCAD) Simulations of Mg2Si/Si Heterojunction Photodetector Based on the Thickness Effect

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5559
Author(s):  
Hong Yu ◽  
Shentong Ji ◽  
Xiangyan Luo ◽  
Quan Xie
Keyword(s):  
Response Time ◽  
Infrared Detectors ◽  
Recovery Time ◽  
Thickness Effect ◽  
Electrical Performance ◽  
Infrared Light ◽  
The Sustainable Development ◽  
Simulation Results ◽  
Technology Cad ◽  
Tcad Simulations

Research on infrared detectors has been widely reported in the literature. For infrared detectors, PbS, InGaAs, PbSe, InSb, and HgxCd1-xTe materials are the most widely used and have been explored for photodetection applications. However, these are toxic and harmful substances which are not conducive to the sustainable development of infrared detectors and are not eco-friendly. Mg2Si is a green, healthy, and sustainable semiconductor material that has the potential to replace these toxic and damaging photoelectric materials, making photoelectric detectors (PDs) green, healthy, and sustainable. In this work, we report on the results of our simulation studies on the PN junction Mg2Si/Si heterojunction PD. A model structure of Mg2Si/Si heterojunction PD has been built. The effects of Mg2Si and Si layer thickness on the optical and electrical performance of Mg2Si/Si heterojunction PD are discussed. For the purpose of this analysis, we consider electrical performance parameters such as I–V curve, external quantum efficiency (EQE), responsivity, noise equivalent power (NEP), detectivity, on-off ratio, response time, and recovery time. The simulation results show that the Mg2Si/Si heterojunction PD shows optimum performance when the thickness of Si and Mg2Si layers are 300 nm and 280 nm, respectively. For the optimized structure, the reverse breakdown voltage was found to be −23.61 V, the forward conduction voltage was 0.51 V, the dark current was 5.58 × 10−13 A, and the EQE was 88.98%. The responsivity was found to be 0.437 A/W, the NEP was 6.38 × 10−12 WHz1/2, and the detectivity was 1.567 × 1011 Jones. With the on-off ratio of 1566, the response time was found to be 0.76 ns and the recovery time was 5.75 ns. The EQE and responsivity peak wavelength of PD show a redshift as the thickness of Mg2Si increases. The Mg2Si heterojunction PD can effectively detect infrared light in the wavelength range of 400 to 1400 nm. The simulation results can be utilized to drive the development of green Mg2Si/Si heterojunction PD in the future.

Butane/Propane Gas Sensing Using Zinc Oxide Film Grown by Successive Ionic Layer Adhesion and Reaction

2016 ◽  
Vol 705 ◽  
pp. 273-277 ◽  
Author(s):  
Emmanuel A. Florido ◽  
Sarah Allyssa Solidum
Keyword(s):  
Zinc Oxide ◽  
Oxide Film ◽  
Response Time ◽  
Recovery Time ◽  
Zno Nanorods ◽  
Hot Water ◽  
Zinc Oxide Film ◽  
Zno Film ◽  
Voltage Output ◽  
Ionic Layer

This study was aimed to test the ability of zinc oxide (ZnO) film fabricated by successive ionic layer adsorption and reaction (SILAR) to detect liquid petroleum gas consisting of a mixture of butane/propane gas. The film was fabricated by alternate dipping of pre-cleaned glass substrates in a sodium zincate bath and in a 95°C hot water bath using an automated dipping machine to control the sequence and dipping time. Scanning electron microscopy (SEM) revealed a uniform film consisting of wurtzite ZnO nanorods for the sample grown using 0.1M concentration of sodium zincate and 200 dippings. Current-voltage characterization of the samples showed an average resistivity of 1.343 Ω-m. EDS analysis of the film confirmed the existence of zinc oxide with 65.9% zinc and 34.1% oxygen. The ZnO film exhibited an ability to detect the gas with an average gas response of 0.44, average response time of 14 seconds and average recovery time of 25 seconds using a gas concentration in air of 1.5 % by volume. Response time is the time for the sensor to reach the peak voltage output from the start of gas exposure while recovery time is the time for the voltage output to return to the initial value without gas when the gas is removed from the chamber. The zinc oxide film also showed a voltage output of 100, 109.31, 118.92, 123.61, 133.5, and 149.52 mV when exposed to percent volume gas concentrations of 0, 0.5, 0.75, 1.0, 1.25, and 1.5, respectively with a correlation coefficient of 0.97. The sensor sensitivity is 32 Δ(mV)/Δ(%conc).

scholarly journals Cost minimization of algorithms for scheduling parallel, single-threaded, heterogeneous, speed-scalable processors

2021 ◽  
Author(s):  
Rashid Khogali
Keyword(s):  
Load Balancing ◽  
Response Time ◽  
Scaling Function ◽  
Unit Price ◽  
Energy Sources ◽  
Speed Scaling ◽  
Computing Architecture ◽  
Performance Metric ◽  
Simulation Results ◽  
Better Than

We synthesize online scheduling algorithms to optimally assign a set of arriving heterogeneous tasks to heterogeneous speed-scalable processors under the single threaded computing architecture. By using dynamic speed-scaling, where each processor's speed is able to dynamically change within hardware and software processing constraints, the goal of our algorithms is to minimize the total financial cost (in dollars) of response time and energy consumption (TCRTEC) of the tasks. In our work, the processors are heterogeneous in that they may differ in their hardware specifications with respect to maximum processing rate, power function parameters and energy sources. Tasks are heterogeneous in terms of computation volume, memory and minimum processing requirements. We also consider that the unit price of response time for each task is heterogeneous because the user may be willing to pay higher/lower unit prices for certain tasks, thereby increasing/decreasing their optimum processing rates. We model the overhead loading time incurred when a task is loaded by a given processor prior to its execution and assume it to be heterogeneous as well. Under the single threaded, single buffered computing architecture, we synthesize the SBDPP algorithm and its two other versions. Its first two versions allow the user to specify the unit price of energy and response time for executing each arriving task. The algorithm's second version extends the functionality of the first by allowing the user or the OS of the computing device to further modify a task's unit price of time or energy in order to achieve a linearly controlled operation point that lies somewhere in the economy-performance mode continuum of a task's execution. The algorithm's third version operates exclusively on the latter. We briefly extend the algorithm and its versions to consider migration, where an unfinished task is paused and resumed on another processor. The SBDPP algorithm is qualitatively compared against its two other versions. The SBDPP dispatcher is analytically shown to perform better than the well known Round Robin dispatcher in terms of the TCRTEC performance metric. Through simulations we deduce a relationship between the arrival rate of tasks, number of processors and response time of tasks. Under the Single threaded, multi-buffered computing architecture we have four contributions that constitute the SMBSPP algorithm. First, we propose a novel task dispatching strategy for assigning the tasks to the processors. Second, we propose a novel preemptive service discipline called Smallest remaining Computation Volume Per unit Price of response Time (SCVPPT) to schedule the tasks on the assigned processor. Third, we propose a dynamic speed-scaling function that explicitly determines the optimum processing rate of each task. Most of the simulations consider both stochastic and deterministic traffic conditions. Our simulation results show that SCVPPT outperforms the two known service disciplines, Shortest Remaining Processing Time (SRPT) and the First Come First Serve (FCFS), in terms of minimizing the TCRTEC performance metric. The results also show that the algorithm's dispatcher drastically outperforms the well known Round Robin dispatcher with cost savings exceeding 100% even when the processors are mildly heterogeneous. Finally, analytical and simulation results show that our speed scaling function performs better than a comparable speed scaling function in current literature. Under a fixed budget of energy, we synthesize the SMBAD algorithm which uses the micro-economic laws of Supply and Demand (LSD) to heuristically adjust the unit price of energy in order to extend battery life and execute more than 50% of tasks on a single processor (under the single threaded, multi buffered computing architecture). By extending all our multiprocessor algorithms to factor independent (battery) energy sources that is associated with each processor, we analytically show that load balancing effects are induced on hetergeneous parallel processors. This happens when the unit price of energy is adjusted by the battery level of each processor in accordance with LSD. Furthermore, we show that a variation of this load balancing effect also occurs when the heterogeneous processors use a single battery as long as they operate at unconstrained processing rates.

scholarly journals Cost minimization of algorithms for scheduling parallel, single-threaded, heterogeneous, speed-scalable processors

2021 ◽  
Author(s):  
Rashid Khogali
Keyword(s):  
Load Balancing ◽  
Response Time ◽  
Scaling Function ◽  
Unit Price ◽  
Energy Sources ◽  
Speed Scaling ◽  
Computing Architecture ◽  
Performance Metric ◽  
Simulation Results ◽  
Better Than

We synthesize online scheduling algorithms to optimally assign a set of arriving heterogeneous tasks to heterogeneous speed-scalable processors under the single threaded computing architecture. By using dynamic speed-scaling, where each processor's speed is able to dynamically change within hardware and software processing constraints, the goal of our algorithms is to minimize the total financial cost (in dollars) of response time and energy consumption (TCRTEC) of the tasks. In our work, the processors are heterogeneous in that they may differ in their hardware specifications with respect to maximum processing rate, power function parameters and energy sources. Tasks are heterogeneous in terms of computation volume, memory and minimum processing requirements. We also consider that the unit price of response time for each task is heterogeneous because the user may be willing to pay higher/lower unit prices for certain tasks, thereby increasing/decreasing their optimum processing rates. We model the overhead loading time incurred when a task is loaded by a given processor prior to its execution and assume it to be heterogeneous as well. Under the single threaded, single buffered computing architecture, we synthesize the SBDPP algorithm and its two other versions. Its first two versions allow the user to specify the unit price of energy and response time for executing each arriving task. The algorithm's second version extends the functionality of the first by allowing the user or the OS of the computing device to further modify a task's unit price of time or energy in order to achieve a linearly controlled operation point that lies somewhere in the economy-performance mode continuum of a task's execution. The algorithm's third version operates exclusively on the latter. We briefly extend the algorithm and its versions to consider migration, where an unfinished task is paused and resumed on another processor. The SBDPP algorithm is qualitatively compared against its two other versions. The SBDPP dispatcher is analytically shown to perform better than the well known Round Robin dispatcher in terms of the TCRTEC performance metric. Through simulations we deduce a relationship between the arrival rate of tasks, number of processors and response time of tasks. Under the Single threaded, multi-buffered computing architecture we have four contributions that constitute the SMBSPP algorithm. First, we propose a novel task dispatching strategy for assigning the tasks to the processors. Second, we propose a novel preemptive service discipline called Smallest remaining Computation Volume Per unit Price of response Time (SCVPPT) to schedule the tasks on the assigned processor. Third, we propose a dynamic speed-scaling function that explicitly determines the optimum processing rate of each task. Most of the simulations consider both stochastic and deterministic traffic conditions. Our simulation results show that SCVPPT outperforms the two known service disciplines, Shortest Remaining Processing Time (SRPT) and the First Come First Serve (FCFS), in terms of minimizing the TCRTEC performance metric. The results also show that the algorithm's dispatcher drastically outperforms the well known Round Robin dispatcher with cost savings exceeding 100% even when the processors are mildly heterogeneous. Finally, analytical and simulation results show that our speed scaling function performs better than a comparable speed scaling function in current literature. Under a fixed budget of energy, we synthesize the SMBAD algorithm which uses the micro-economic laws of Supply and Demand (LSD) to heuristically adjust the unit price of energy in order to extend battery life and execute more than 50% of tasks on a single processor (under the single threaded, multi buffered computing architecture). By extending all our multiprocessor algorithms to factor independent (battery) energy sources that is associated with each processor, we analytically show that load balancing effects are induced on hetergeneous parallel processors. This happens when the unit price of energy is adjusted by the battery level of each processor in accordance with LSD. Furthermore, we show that a variation of this load balancing effect also occurs when the heterogeneous processors use a single battery as long as they operate at unconstrained processing rates.

CO Sensing Properties of La1-xCaxFeO3 Perovskite Nanocrystalline Materials

2011 ◽  
Vol 495 ◽  
pp. 323-326 ◽  
Author(s):  
Ming Zhao ◽  
Li Hui Sun ◽  
Ji Fan Hu ◽  
Hong Wei Qin
Keyword(s):  
Response Time ◽  
Nanocrystalline Materials ◽  
Recovery Time ◽  
Operating Temperature ◽  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Orthorhombic Structure ◽  
Gel Method ◽  
Sensing Properties ◽  
Sol Gel Method

The La1-xCaxFeO3 nanocrystalline powders were prepared by sol-gel method. These powders crystallized as perovskite orthorhombic structure. With an increase of Ca content, the resistance of La1-xCaxFeO3 sensors in air decreases at first, undergoes a minimum at x=0.3, and then increases again. La1-xCaxFeO3-based sensors show sensitive responses to CO. Among those La1-xCaxFeO3-based sensors, the sensor with x=0.2 shows the highest response to 200 ppm CO at operating temperatures below 325°C. The highest response S=(RCO-Rair)/RCO for the La0.8Ca0.2FeO3 based sensor to 200 ppm CO is 87% with response time 15 s and recovery time 60 s at an operating temperature of 100°C.

Design and Robustness of Quilt Packaging Superconnect

2012 ◽  
Vol 2012 (1) ◽  
pp. 000524-000530
Author(s):  
M. Ashraf Khan ◽  
Jason M. Kulick ◽  
Alfred M. Kriman ◽  
Gary H. Bernstein
Keyword(s):  
Thermal Cycling ◽  
High Speed ◽  
Low Cycle Fatigue ◽  
Simulation Models ◽  
Electrical Performance ◽  
Cycle Fatigue ◽  
Signal Delay ◽  
Thermal Reliability ◽  
Simulation Results ◽  
Quilt Packaging

Quilt Packaging (QP) is a novel high-speed superconnect (i.e. direct interchip interconnect), developed to improve electrical performance — signal delay, power loss, etc. Ultrahigh bandwidth has already been demonstrated for QP, but its unique structure requires thermal reliability issues to be studied. To this end, simulation models were developed to study the robustness of QP. QP structures were fabricated, and thermal cycling tests were performed focusing on the reliability for various shapes of nodules, the basic physical interconnect unit of QP. Simulations were performed to determine stress over a range of temperatures and estimate low cycle fatigue lifetimes. Simulations considered two types of solder and several adhesives. Thermal cycling experiments indicate that QP provides a robust structure, in agreement with the simulation results.

scholarly journals STUDI ANALISIS UFR (UNDER FREQUENCY RELAY) PADA GARDU INDUK PESANGGARAN

2019 ◽  
Vol 6 (2) ◽  
pp. 45
Author(s):  
Bhrama Sakti K.P. ◽  
A.A. Gede Maharta Pemayun ◽  
I Gede Dyana Arjana
Keyword(s):  
Power Plant ◽  
Power System ◽  
Electric Power ◽  
Recovery Time ◽  
Electric Power System ◽  
Calculation Results ◽  
Working Principle ◽  
Simulation Results ◽  
System Frequency ◽  
Frequency State

The disruption of the electric power system due to overcurrent causes a trip to the 3rd generator of pesanggaran power plant . This causes a decrease in frequency due to the system losing its supply. Frequency interference can be detected automatically with UFR (Under Frequency Relay). The working principle of UFR is to compare the value of the system frequency and the value of the frequency setting. The comparison will determine how much load is released to balance the generator supply. This study analyzes UFR performance at Pesanggaran Substation by simulating a case of the generator being released so as to produce a decreased system frequency state. The method used is by comparing the ETAP simulation results and calculation results. The results of the comparison obtained the system recovery time when the conditions (gen1 tripped), (gen1 and gen2 tripped), and (gen1, gen2, and gen3 tripped), each is 1.171s; 4,531s; and 4,514s.

scholarly journals Enhanced Humidity Sensing Response of SnO2/Silicon Nanopillar Array by UV Irradiation

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2141 ◽  
Author(s):  
Wei Li ◽  
Linlin Wang ◽  
Yun Cai ◽  
Peifeng Pan ◽  
Jinze Li ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Response Time ◽  
Specific Surface ◽  
Uv Irradiation ◽  
Recovery Time ◽  
Room Temperature ◽  
Uv Light ◽  
Humidity Sensing ◽  
Potential Applications ◽  
Humidity Sensitivity

In this work, a silicon nanopillar array was created with nanosphere lithography. SnO2 film was deposited on this nanostructure by magnetron sputtering to form an SnO2/silicon nanopillar array sensor. The humidity sensitivity, response time, and recovery time were all measured at room temperature (25 °C) with UV or without UV irradiation. As a result, the humidity sensitivity properties were improved by enlarging the specific surface area with ordered nanopillars and irradiating with UV light. These results indicate that nanostructure sensors have potential applications in the field of sensors.

scholarly journals Control Technology of Surface Movement Scope with Directional Hydraulic Fracturing Technology in Longwall Mining: A Case Study

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3480 ◽  
Author(s):  
Zhanjie Feng ◽  
Wenbing Guo ◽  
Feiya Xu ◽  
Daming Yang ◽  
Weiqiang Yang
Keyword(s):  
Numerical Simulation ◽  
Hydraulic Fracturing ◽  
Longwall Mining ◽  
Numerical Models ◽  
Surface Subsidence ◽  
The Sustainable Development ◽  
Surface Movement ◽  
Directional Hydraulic Fracturing ◽  
Simulation Results ◽  
Overlying Strata

Mining-induced surface subsidence causes a series of environmental hazards and social problems, including farmland destruction, waterlogging and building damage in the subsidence area. To reduce mining damages, an innovative method of controlling the surface movement scope via artificial weak planes generated by hydraulic fracturing technology was proposed in this paper. Numerical models were built to analyze the influence of weak planes with different heights and dips on the overlying strata movement. The numerical simulation results showed that the weak planes structure cut off the development of the overlying strata displacement to the surface and affected the surface movement scope. When the weak planes’ dips were bigger than the angle of critical deformation, with the increase of the weak planes’ heights (0–120 m) the advance angle of influence changed from 53.61° to 59.15°, and the advance distance of influence changed from 173.31 m to 140.27 m which decreased by 30.04 m. In applications at Sihe coal mine in China, directional hydraulic fracturing technology was used in panel 5304 to form artificial weak planes in overlying strata. The measured surface subsidence and deformation value met the numerical simulation results and the mining-induced surface movement scope reduced. Moreover, no damage occurred to the surface buildings which were predicted to be in the affected area after extraction. This technology provided a new method to protect the surface structures from damages and had great benefits for the sustainable development of coal mines.

THE RESEARCH OF QUENCHING EFFECT IN GRADIENT-BANDGAP CdSSe NANOWIRE

2019 ◽  
Vol 26 (05) ◽  
pp. 1850194
Author(s):  
DUNWEI LIU ◽  
WENJIE ZHOU ◽  
XIA ZHOU ◽  
HUIYAO AN ◽  
YUHUA CHENG ◽  
...  
Keyword(s):  
Infrared Detectors ◽  
Gold Catalysis ◽  
Infrared Light ◽  
Semiconductor Materials ◽  
Optical Intensity ◽  
Defect Level ◽  
Trap Energy ◽  
Quenching Effect ◽  
Power Injection ◽  
Recombination Centers

Quenching effect of photoconductive semiconductor material has important applications in areas like detecting semiconductor defect and infrared light. In this paper, vapor–liquid–solid (VLS) method is improved to grow nanowires by using a heat resisting quartz tube as the vessel. With the conditions of gold catalysis, appropriate temperature, and ease of handling, gradient-bandgap CdSSe nanowires were grown successfully. We study the quenching effect of different component parts of the nanowire, respectively, and find that the quenching degree increases with the increasing optical intensities of different bandgap nanowires when the power injection is below 10[Formula: see text][Formula: see text]W. However, since more recombination centers would turn into the trap energy level centers leading to more electrons to jump into the conduction band with the increasing density of CdS, the peak of quenched rate for 90% CdS proportion nanowire arrives earlier than 90% CdSe proportion, and the peak of quenched rate for CdSe still does not appear even when the optical intensity reaches 10[Formula: see text][Formula: see text]W. Our experiment provides an effective and convenient method for the defect-level detection of semiconductor materials, and can also develop high resolution infrared detectors under the material limitation conditions.

scholarly journals Self-Filtering Monochromatic Infrared Detectors Based on Bi2Se3 (Sb2Te3)/Silicon Heterojunctions

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1771
Author(s):  
Xujie Pan ◽  
Jing He ◽  
Lei Gao ◽  
Handong Li
Keyword(s):  
Response Time ◽  
Infrared Detectors ◽  
Near Infrared ◽  
Nir Light ◽  
Photoelectric Properties ◽  
Detection Response ◽  
Silicon Heterojunctions ◽  
Surface Modified ◽  
High Pass ◽  
Back Illuminated

This paper focuses on the photoelectric properties of heterostructures formed by surface-modified Si (111) and hexagonal, quintuple-layered selenides (Bi2Se3 and Sb2Te3). It was shown that H-passivated Si (111) can form robust Schottky junctions with either Bi2Se3 or Sb2Te3. When back illuminated (i.e., light incident towards the Si side of the junction), both the Bi2Se3/Si and Sb2Te3/Si junctions exhibited significant photovoltaic response at 1030 nm, which is right within the near-infrared (NIR) light wavelength range. A maximum external quantum efficiency of 14.7% with a detection response time of 2 ms for Bi2Se3/Si junction, and of 15.5% with a 0.8 ms response time for the Sb2Te3/Si junction, were achieved. Therefore, utilizing Si constituents as high-pass filters, the Bi2Se3 (Sb2Te3)/Si heterojunctions can serve as monochromatic NIR photodetectors.

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