Analysis of Tunneling Piezoresistive Effect of P-Type Polysilicon Nanofilms

2009 ◽  
Vol 60-61 ◽  
pp. 89-93 ◽  
Author(s):  
Xue Bin Lu ◽  
Xiao Wei Liu ◽  
Rong Yan Chuai ◽  
Chang Zhi Shi ◽  
Ming Xue Huo ◽  
...  

The polysilicon nanofilms have significant piezoresistive characteristics. In this paper, an analysis of tunneling piezoresistive effect of p-type polysilicon nanofilms is presented based on the experimental data. The analysis results show that the tunneling piezoresistive effect is much remarkable than piezoresistive effect of neutral region, and the former is about 1.3 to 1.5 times of the latter. The higher is doping concentration, the more remarkable tunneling piezoresistive effect is. This advantage can be utilized to improve the temperature characteristics of polysilicon piezoresistive sensor.

2009 ◽  
Vol 60-61 ◽  
pp. 84-88 ◽  
Author(s):  
Xiao Wei Liu ◽  
Xue Bin Lu ◽  
Rong Yan Chuai ◽  
Chang Zhi Shi ◽  
Ming Xue Huo ◽  
...  

The gauge factor and nonlinearity of 80nm polysilicon nanofilms with different doping concentration were tested. The experimental results show that, from 8.1×1018cm-3 to 2.0×1020cm-3, the gauge factors first increase then decrease, which like the common polysilicon films (thickness is larger than 100nm). From 2.0×1020cm-3 to 7.1×1020cm-3, the gauge factors do not change with doping concentration almost, which can be explained by tunneling piezoresistive theory. When doping concentration is low than 4.1×1019cm-3, the nonlinearities are big, and the nonlinearities become small when doping concentration is high than 4.1×1019cm-3. The nonlinearity is related to the occupied condition of trapping states in grain boundary. The longitudinal gauge factor and nonlinearity are smaller than transverse ones. Take the gauge factor and nonlinearity both into consideration, the optimal doping concentration should be 4.1×1019cm-3. The conclusions are very useful for design and fabrication of polysilicon nanofilms piezoresistive sensor.


2014 ◽  
Vol 981 ◽  
pp. 875-878 ◽  
Author(s):  
Xue Bin Lu ◽  
Lin Hai Cui ◽  
Ming Yuan Ren

In order to take good advantage of polysilicon nanofilm, optimized technical characteristics of the polysilicon nanofilm are very necessary to investigated. In this paper, the polysilicon nanofilms were prepared under different technical parameters, including thickness and doping concentration, which are very important for preparation of the nanofilm. The experimental results of piezoresistive and temperature characteristics show that the optimized technical characteristics are followed, the thickness is about 90nm, and the doping concentration is about 4.1×?1019cm-3 or between 2.0×?1020cm-3 and 4.1×?1020cm-3 from different point of view. The investigations of optimized technical characteristics are very useful for application of the polysilicon nanofilm to piezoresistive sensor.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2152
Author(s):  
E. M. Mkawi ◽  
Y. Al-Hadeethi ◽  
R. S. Bazuhair ◽  
A. S. Yousef ◽  
E. Shalaan ◽  
...  

In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells’ performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer’s active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV–visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer’s doping concentration played a definitive role in improving the device’s performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.


1981 ◽  
Vol 5 ◽  
Author(s):  
L. J. Cheng ◽  
C. M. Shyu

ABSTRACTWe have studied the photoconductivity of grain boundaries in p–type silicon. The result demonstrates the applicability of the technique for the measurement of minority carrier recombination velocity at the grain boundary. The experimental data are consistent with the thought that the recombination velocity increases with the boundary state density and light intensity.


2004 ◽  
Vol 815 ◽  
Author(s):  
Ying Gao ◽  
Zehong Zhang ◽  
Robert Bondokov ◽  
Stanislav Soloviev ◽  
Tangali Sudarshan

AbstractMolten KOH etchings were implemented to delineate structural defects in the n- and ptype 4H-SiC samples with different doping concentrations. It was observed that the etch preference is significantly influenced by both the doping concentrations and the conductivity types. The p-type Si-face 4H-SiC substrate has the most preferential etching property, while it is least for n+ samples. It has been clearly demonstrated that the molten KOH etching process involves both chemical and electrochemical processes, during which isotropic etching and preferential etching are competitive. The n+ 4H-SiC substrate was overcompensated via thermal diffusion of boron to p-type and followed by molten KOH etching. Three kinds of etch pits corresponding to threading screw, threading edge, and basal plane dislocations are distinguishably revealed. The same approach was also successfully employed in delineating structural defects in (0001) C-face SiC wafers.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 216
Author(s):  
Yongwei Li ◽  
Ting Liang ◽  
Cheng Lei ◽  
Qiang Li ◽  
Zhiqiang Li ◽  
...  

In this study, a preparation method for the high-temperature pressure sensor based on the piezoresistive effect of p-type SiC is presented. The varistor with a positive trapezoidal shape was designed and etched innovatively to improve the contact stability between the metal and SiC varistor. Additionally, the excellent ohmic contact was formed by annealing at 950 °C between Ni/Al/Ni/Au and p-type SiC with a doping concentration of 1018cm−3. The aging sensor was tested for varistors in the air of 25 °C–600 °C. The resistance value of the varistors initially decreased and then increased with the increase of temperature and reached the minimum at ~450 °C. It could be calculated that the varistors at ~100 °C exhibited the maximum temperature coefficient of resistance (TCR) of ~−0.35%/°C. The above results indicated that the sensor had a stable electrical connection in the air environment of ≤600 °C. Finally, the encapsulated sensor was subjected to pressure/depressure tests at room temperature. The test results revealed that the sensor output sensitivity was approximately 1.09 mV/V/bar, which is better than other SiC pressure sensors. This study has a great significance for the test of mechanical parameters under the extreme environment of 600 °C.


2019 ◽  
Vol 14 (1) ◽  
pp. 1-6
Author(s):  
Alberto Vinícius Oliveira ◽  
Guilherme Vieira Gonçalves ◽  
Paula Ghedini Der Agopian ◽  
João Antonio Martino ◽  
Jérôme Mitard ◽  
...  

The implementation of a barrier potential layer underneath the channel region, well known as Ground Plane (GP) implantation, and its influence on the performance of relaxed germanium pFinFET devices is investigated in this manuscript. This study aims to explain the fin width dependence of the threshold voltage from experimental data and evaluates the ground plane doping concentration and its depth influence on relaxed p-type channel germanium FinFET parameters, as threshold voltage, transconductance and subthreshold swing, through Technology Computer-Aided Design (TCAD) numerical simulations. The threshold voltage variation reaches up to 80 mV from the narrowest device to the widest one, considering the studied range of ground plane doping concentration. Concerning the subthreshold swing parameter, neither the GP doping concentration, nor its depth play a significant role since the electrostatic coupling is predominant.


2017 ◽  
Vol 38 (7) ◽  
pp. 955-958 ◽  
Author(s):  
Tuan-Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Toan Dinh ◽  
Jisheng Han ◽  
Sima Dimitrijev ◽  
...  

1993 ◽  
Vol 329 ◽  
Author(s):  
Wen P. Shen ◽  
Hoi S. Kwok

AbstractCdS thin films with doping concentration as high as 1017 cm-3 for p-type or 1021 cm-3 for n-type were achieved by pulsed excimer laser deposition without any post-annealing process. These films were grown on InP or GaAs substrates with good crystalline quality. By using this technique, CdS thin film p-n junctions were produced successfully.


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