Surface state controlled ultrahigh selectivity and sensitivity for UV photodetectors based on individual SnO2 nanowires

2016 ◽  
Vol 4 (36) ◽  
pp. 8399-8406 ◽  
Author(s):  
Haiping Shi ◽  
Baochang Cheng ◽  
Qiangsheng Cai ◽  
Xiaohui Su ◽  
Yanhe Xiao ◽  
...  

Surface states are utilized for the development of high-performance photodetectors based on individual SnO2 nanowires. Their photodetectivity strongly depends on externally applied bias voltage and illuminated light intensity.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Jinlong Jiang ◽  
Qiong Wang ◽  
Yubao Wang ◽  
Zhang Xia ◽  
Hua Yang ◽  
...  

The titanium- and silicon-codoped a-C:H films were prepared at different applied bias voltage by magnetron sputtering TiSi target in argon and methane mixture atmosphere. The influence of the applied bias voltage on the composition, surface morphology, structure, and mechanical properties of the films was investigated by XPS, AFM, Raman, FTIR spectroscopy, and nanoindenter. The tribological properties of the films were characterized on an UMT-2MT tribometer. The results demonstrated that the film became smoother and denser with increasing the applied bias voltage up to −200 V, whereas surface roughness increased due to the enhancement of ion bombardment as the applied bias voltage further increased. The sp3carbon fraction in the films monotonously decreased with increasing the applied bias voltage. The film exhibited moderate hardness and the superior tribological properties at the applied bias voltage of −100 V. The tribological behaviors are correlated to the H/E or H3/E2ratio of the films.


2005 ◽  
Vol 20 (1) ◽  
pp. 62-67 ◽  
Author(s):  
E. György ◽  
A. Pérez del Pino ◽  
P. Serra ◽  
J.L. Morenza

Titanium targets with a bias voltage ranging from −500 to +500 V were submitted to multipulse high repetition rate Nd:yttrium aluminum garnet (YAG; λ = 1.064 μm, τ ∼ 300 ns, ν = 30 kHz) laser irradiations in nitrogen at intensity values below the single-pulse melting threshold. The morphology of the TiN structures formed under the cumulative action of the laser pulses on the surface of the unbiased and biased targets was investigated by profilometry and scanning electron microscopy. Under these irradiation conditions, a specific columnar surface microrelief developed. The height of the microcolumns reached about 10–15 μm, and their diameter about 1–2 μm. The development of TiN microcolumns was enhanced by the applied bias voltage. The enhancement in the negative biased samples was stronger than that in the positive biased ones.


Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Shubham Shubham ◽  
Yoonho Seo ◽  
Vahid Naderyan ◽  
Xin Song ◽  
Anthony J. Frank Frank ◽  
...  

Audio applications such as mobile phones, hearing aids, true wireless stereo earphones, and Internet of Things devices demand small size, high performance, and reduced cost. Microelectromechanical system (MEMS) capacitive microphones fulfill these requirements with improved reliability and specifications related to sensitivity, signal-to-noise ratio (SNR), distortion, and dynamic range when compared to their electret condenser microphone counterparts. We present the design and modeling of a semiconstrained polysilicon diaphragm with flexible springs that are simply supported under bias voltage with a center and eight peripheral protrusions extending from the backplate. The flexible springs attached to the diaphragm reduce the residual film stress effect more effectively compared to constrained diaphragms. The center and peripheral protrusions from the backplate further increase the effective area, linearity, and sensitivity of the diaphragm when the diaphragm engages with these protrusions under an applied bias voltage. Finite element modeling approaches have been implemented to estimate deflection, compliance, and resonance. We report an 85% increase in the effective area of the diaphragm in this configuration with respect to a constrained diaphragm and a 48% increase with respect to a simply supported diaphragm without the center protrusion. Under the applied bias, the effective area further increases by an additional 15% as compared to the unbiased diaphragm effective area. A lumped element model has been also developed to predict the mechanical and electrical behavior of the microphone. With an applied bias, the microphone has a sensitivity of −38 dB (ref. 1 V/Pa at 1 kHz) and an SNR of 67 dBA measured in a 3.25 mm ´ 1.9 mm ´ 0.9 mm package including an analog ASIC.


VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 149-153
Author(s):  
M. Girlanda ◽  
M. Macucci

We present a numerical simulation of the operation of a chain of 3 Quantum Cellular Automanton (QCA) cells, with the inclusion of a realistic procedure to enforce, with an externally applied bias voltage unbalance, the polarization of the first cell. The polarization state is shown to propagate correctly, as long as the bias unbalance applied to the electrodes of the first cell is not so large as to directly perturb nearby cells. The addition of dummy cells is needed to balance the asymmetries existing at the ends of a chain: this is an indication of further difficulties, that may become relevant if fabrication of more complex arrays is attempted.


1996 ◽  
Vol 78 (1-3) ◽  
pp. 31-36 ◽  
Author(s):  
Yin Dachuan ◽  
Xu Niankan ◽  
Liu Zhengtang ◽  
Han Yong ◽  
Zheng Xiulin

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