scholarly journals Responsivity Dependent Anodization Current Density of Nanoporous Silicon Based MSM Photodetector

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Batool Eneaze B. Al-Jumaili ◽  
Zainal A. Talib ◽  
Asmiet Ramizy ◽  
Naser M. Ahmed ◽  
L. Y. Josephine ◽  
...  
Keyword(s):  
Current Density ◽  
High Speed ◽  
Fast Response ◽  
Density Variation ◽  
Nanoporous Silicon ◽  
Barrier Formation ◽  
Metal Semiconductor Metal ◽  
Msm Photodetector ◽  
Scherrer Formula ◽  
Silicon Based

Achieving a cheap and ultrafast metal-semiconductor-metal (MSM) photodetector (PD) for very high-speed communications is ever-demanding. We report the influence of anodization current density variation on the response of nanoporous silicon (NPSi) based MSM PD with platinum (Pt) contact electrodes. Such NPSi samples are grown from n-type Si (100) wafer using photoelectrochemical etching with three different anodization current densities. FESEM images of as-prepared samples revealed the existence of discrete pores with spherical and square-like shapes. XRD pattern displayed the growth of nanocrystals with (311) lattice orientation. The nanocrystallite sizes obtained using Scherrer formula are found to be between 20.8 nm and 28.6 nm. The observed rectifying behavior in theI-Vcharacteristics is ascribed to the Pt/PSi/n-Si Schottky barrier formation, where the barrier height at the Pt/PSi interface is estimated to be 0.69 eV. Furthermore, this Pt/PSi/Pt MSM PD achieved maximum responsivity of 0.17 A/W and quantum efficiency as much as 39.3%. The photoresponse of this NPSi based MSM PD demonstrated excellent repeatability, fast response, and enhanced saturation current with increasing anodization current density.

scholarly journals Phosphorene-assisted silicon photonic modulator with fast response time

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1973-1979 ◽  
Author(s):  
Zhao Cheng ◽  
Rui Cao ◽  
Jia Guo ◽  
Yuhan Yao ◽  
Kangkang Wei ◽  
...  
Keyword(s):  
Response Time ◽  
High Speed ◽  
Fast Response ◽  
Optical Modulator ◽  
High Electron ◽  
Optical Modulators ◽  
Strong Light ◽  
Optical Signals ◽  
All Optical ◽  
Silicon Based

AbstractAll-optical modulators avoid the conversion from external electronic signals to optical signals and thus have the potential to achieve an energy-efficient high-speed photonic system. Phosphorene recently debuted as an attractive material that exhibits outstanding high electron mobility, strong light-matter interaction and modifiable bandgap, making it ideal for all-optical modulators. In this paper, by incorporating a phosphorene and silicon-based micro-ring resonator (MRR), we first propose and experimentally demonstrate a unique phosphorene-integrated all-optical modulator in telecommunications. By utilizing a phosphorene thin film with an average thickness of 22 nm as the absorption material, the rise time of only 479 ns and decay time of 113 ns are achieved, which is the fastest reported response time in the family of phosphorene modulators. The corresponding 3 dB bandwidth is larger than 2.5 MHz, and it exhibits a low-loss performance benefited from its finite bandgap. The proposed phosphorene/MRR hybrid modulator may have potential in the applications of all-optical interconnections.

Photo-electrochemically synthesized light emtting nanoporous silicon based UV photodetector: influence of current density

2017 ◽  
Vol 4 (11) ◽  
pp. 116203 ◽  
Author(s):  
Asad A Thahe ◽  
Noriah Bidin ◽  
Z Hassan ◽  
Hazri Bakhtiar ◽  
M A Qaeed ◽  
...  
Keyword(s):  
Current Density ◽  
Nanoporous Silicon ◽  
Uv Photodetector ◽  
Silicon Based

Direct Current Deadbeat Predictive Controller for BLDC Motor Using Single DC-Link Current Sensor

2020 ◽  
Vol 38 (8A) ◽  
pp. 1187-1199
Author(s):  
Qaed M. Ali ◽  
Mohammed M. Ezzalden
Keyword(s):  
Control System ◽  
High Speed ◽  
Fast Response ◽  
Bldc Motor ◽  
Current Controller ◽  
Three Phase ◽  
Predictive Controller ◽  
Two Phases ◽  
Dc Current ◽  
Three Phase Inverter

BLDC motors are characterized by electronic commutation, which is performed by using an electric three-phase inverter. The direct control system of the BLDC motor consists of double loops; including the inner-loop for current regulating and outer-loop for speed control. The operation of the current controller requires feedback of motor currents; the conventional current controller uses two current sensors on the ac side of the inverter to measure the currents of two phases, while the third current would be accordingly calculated. These two sensors should have the same characteristics, to achieve balanced current measurements. It should be noted that the sensitivity of these sensors changes with time. In the case of one sensor fails, both of them must be replaced. To overcome this problem, it is preferable to use one sensor instead of two. The proposed control system is based on a deadbeat predictive controller, which is used to regulate the DC current of the BLDC motor. Such a controller can be considered as digital controller mode, which has fast response, high precision and can be easily implemented with microprocessor. The proposed control system has been simulated using Matlab software, and the system is tested at a different operating condition such as low speed and high speed.

Experimental Investigation During Stall and Surge in a Transonic Fan Stage and Rotor-Only Configuration

2006 ◽  
Author(s):  
A. J. Gannon ◽  
G. V. Hobson ◽  
R. P. Shreeve ◽  
I. J. Villescas
Keyword(s):  
High Speed ◽  
Fast Response ◽  
Pressure Measurements ◽  
Post Processing ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
The Difference ◽  
Data Signal ◽  
Transonic Fan ◽  
Casing Pressure

High-speed pressure measurements of a transonic compressor rotor-stator stage and rotor-only configuration during stall and surge are presented. Rotational speed data showed the difference between the rotor-only case and rotor-stator stage. The rotor-only case stalled and remained stalled until the control throttle was opened. In the rotor-stator stage the compressor surged entering a cyclical stalling and then un-stalling pattern. An array of pressure probes was mounted in the case wall over the rotor for both configurations of the machine. The fast response probes were sampled at 196 608 Hz as the rotor was driven into stall. Inspection of the raw data signal allowed the size and speed of the stall cell during its growth to be investigated. Post-processing of the simultaneous signals of the casing pressure showed the development of the stall cell from the point of inception and allowed the structure of the stall cell to be viewed.

Silicon-based nonlinear optical devices for high-speed optical communications

2008 ◽  
Author(s):  
Haisheng Rong ◽  
Simon Ayotte ◽  
Shengbo Xu ◽  
Oded Cohen ◽  
Mario Paniccia
Keyword(s):  
Optical Communications ◽  
High Speed ◽  
Nonlinear Optical ◽  
Optical Devices ◽  
Nonlinear Optical Devices ◽  
Silicon Based

Estimation of Time Variation of Current Density in a 50 kA Lightning Impulse Arc using High Speed Cameras

2021 ◽  
Author(s):  
Tomoyuki Nakano ◽  
Masashi Kotari ◽  
Toshiya Ohtaka ◽  
Yutaka Goda ◽  
Mikimasa Iwata
Keyword(s):  
Current Density ◽  
Time Variation ◽  
High Speed ◽  
Lightning Impulse ◽  
Estimation Of Time

Stall Inception in a High Speed Centrifugal Compressor During Speed Transients

2017 ◽  
Author(s):  
Fangyuan Lou ◽  
John C. Fabian ◽  
Nicole L. Key
Keyword(s):  
Heat Transfer ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Flow Instability ◽  
Leading Edge ◽  
Fast Response ◽  
Rotating Stall ◽  
Transient Performance ◽  
Stall Inception ◽  
Pressure Transducers

The inception and evolution of rotating stall in a high-speed centrifugal compressor are characterized during speed transients. Experiments were performed in the Single Stage Centrifugal Compressor (SSCC) facility at Purdue University and include speed transients from sub-idle to full speed at different throttle settings while collecting transient performance data. Results show a substantial difference in the compressor transient performance for accelerations versus decelerations. This difference is associated with the heat transfer between the flow and the hardware. The heat transfer from the hardware to the flow during the decelerations locates the compressor operating condition closer to the surge line and results in a significant reduction in surge margin during decelerations. Additionally, data were acquired from fast-response pressure transducers along the impeller shroud, in the vaneless space, and along the diffuser passages. Two different patterns of flow instabilities, including mild surge and short-length-scale rotating stall, are observed during the decelerations. The instability starts with a small pressure perturbation at the impeller leading edge and quickly develops into a single-lobe rotating stall burst. The stall cell propagates in the direction opposite of impeller rotation at approximately one third of the rotor speed. The rotating stall bursts are observed in both the impeller and diffuser, with the largest magnitudes near the diffuser throat. Furthermore, the flow instability develops into a continuous high frequency stall and remains in the fully developed stall condition.

GaN MSM UV Sensor Using Multi-Layer Graphene Schottky Electrodes

2013 ◽  
Vol 481 ◽  
pp. 146-149 ◽  
Author(s):  
Chang Ju Lee ◽  
Hyeon Gu Cha ◽  
Seul Ki Hong ◽  
Seung Hyun Doh ◽  
Yi Sak Koo ◽  
...  
Keyword(s):  
Current Density ◽  
Applied Bias ◽  
Uv Sensor ◽  
Response Characteristics ◽  
Layer Graphene ◽  
Metal Type ◽  
Metal Semiconductor Metal ◽  
Uv Visible ◽  
Uv Response ◽  
First Time

We demonstrated a metal-semiconductor-metal type GaN UV sensor for the first time by using multi-layer graphene as a Schottky electrode. Multi-layer graphene shows good Schottky electrode characteristic and fabricated UV sensor shows good UV response characteristics. The maximum dark current density and photo-responsive current density were 6.42 × 10-9 A/cm2 and 5.57 × 10-5 A/cm2 at the 10 V bias, respectively. UV/visible rejection ratios were higher than 103 with each applied bias from 1 V to 15 V.

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