SiC Nanowire Film Photodetectors: A Promising Candidate Toward High Temperature Photodetectors

2016 ◽  
Vol 16 (4) ◽  
pp. 3796-3801 ◽  
Author(s):  
Haining Chong ◽  
Huijun Yang ◽  
Weiyou Yang ◽  
Jinju Zheng ◽  
Minghui Shang ◽  
...  

In this study, UV photodetectors (PDs) based on SiC nanowire films have been successfully prepared by a simple and low-cost drip-coating method followed by sintering at 500 °C. The corresponding electrical characterizations clearly demonstrate that the SiC nanowire based PD devices can be regarded as a promising candidate for UV PDs. The PDs can exhibit the excellent performances of fast, high sensitivity, linearity, and stable response, which can thus achieve on-line monitoring of weak UV light. Furthermore, the SiC nanowire-based PDs enable us to fabricate detectors working under high temperature as high as 150 °C. The high photosensitivity and rapid photoresponse for the PDs can be attributed to the superior single crystalline quality of SiC nanowires and the ohmic contact between the electrodes and nanowires.

2019 ◽  
Vol 963 ◽  
pp. 832-836 ◽  
Author(s):  
Shuo Ben Hou ◽  
Per Erik Hellström ◽  
Carl Mikael Zetterling ◽  
Mikael Östling

This paper presents our in-house fabricated 4H-SiC n-p-n phototransistors. The wafer mapping of the phototransistor on two wafers shows a mean maximum forward current gain (βFmax) of 100 at 25 °C. The phototransistor with the highest βFmax of 113 has been characterized from room temperature to 500 °C. βFmax drops to 51 at 400 °C and remains the same at 500 °C. The photocurrent gain of the phototransistor is 3.9 at 25 °C and increases to 14 at 500 °C under the 365 nm UV light with the optical power of 0.31 mW. The processing of the phototransistor is same to our 4H-SiC-based bipolar integrated circuits, so it is a promising candidate for 4H-SiC opto-electronics on-chip integration.


2019 ◽  
Vol 36 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Chee Yong Fong ◽  
Sha Shiong Ng ◽  
NurFahana Mohd Amin ◽  
Fong Kwong Yam ◽  
Zainuriah Hassan

Purpose This study aims to explore the applicability of the sol-gel-derived GaN thin films for UV photodetection. Design/methodology/approach GaN-based ultraviolet (UV) photodetector with Pt Schottky contacts was fabricated and its applicability was investigated. The current-voltage (I-V) characteristics of the GaN-based UV photodetector under the dark current and photocurrent were measured. Findings The ideality factors of GaN-based UV photodetector under dark current and photocurrent were 6.93 and 5.62, respectively. While the Schottky barrier heights (SBH) for GaN-based UV photodetector under dark current and photocurrent were 0.35 eV and 0.34 eV, respectively. The contrast ratio and responsivity of this UV photodetector measured at 5 V were found to be 1.36 and 1.68 μA/W, respectively. The photoresponse as a function of time was measured by switching the UV light on and off continuously at different forward biases of 1, 3 and 6 V. The results showed that the fabricated UV photodetector has reasonable stability and repeatability. Originality/value This work demonstrated that GaN-based UV photodetector can be fabricated by using the GaN thin film grown by low-cost and simple sol-gel spin coating method.


2013 ◽  
Vol 667 ◽  
pp. 384-387
Author(s):  
Mohamed Zahidi Musa ◽  
Mohamad Hafiz Mamat ◽  
Mohamad Rusop

The electrical properties of nanostructured Aluminum (Al) doped Zinc Oxide (ZnO) thin films based ultraviolet (UV) sensor prepared by sol-gel spin-coating method have been investigated. Uniform nanoparticles Al doped ZnO have been deposited with high absorption coefficient at UV region and low absorption coefficient properties in visible and near-infrared (NIR) region. I-V spectra show high sensitivity characteristic of UV sensor with fast response after UV light exposure.


2007 ◽  
Vol 336-338 ◽  
pp. 1477-1480
Author(s):  
Hua Tao Wang ◽  
Zhi Peng Xie ◽  
Wei You Yang ◽  
Guo Quan Liu ◽  
Li Nan An

A novel process with low cost to fabricate SiCN MEMS based on UV lithographic technique is present in this paper. The prepared MEMS are very promising to be used in high-temperature environments. By adding a photo initiator to the polysilazane precursor, the precursor becomes UV-sensitive and can be solidified upon exposure to UV light, which leads to the formation of UV photo lithographical patterns. Key issues of the fabrication process are investigated and various SiCN MEMS structures are fabricated by this technique.


2016 ◽  
Vol 5 (1) ◽  
pp. 127-131
Author(s):  
Jeffrey Olfert ◽  
Brian Luloff ◽  
Dan MacDonald ◽  
Robert Lumsden

Magneto-resistive sensors are rapidly gaining favour for magnetic field sensing applications owing to their high sensitivity, small size, and low cost. Their metallic, nonsemiconductor construction makes them excellent candidates for use in the harsh environments present in nuclear and space applications. In this work, a commercially available magneto-resistive sensor was irradiated up to a total gamma dose of 2 MGy (200 Mrad), and online testing was performed to monitor the sensor throughout the irradiation to detect any degradation. No significant evidence of degradation of the sensor characteristics was observed. A very small (< 1%) change in the bridge balance of the sensor as a function of accumulated dose was detected.


2013 ◽  
Vol 20 (3) ◽  
pp. 91-106 ◽  
Author(s):  
Rachel Pizarek ◽  
Valeriy Shafiro ◽  
Patricia McCarthy

Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most.


Author(s):  
Gennadiy Valentinovich Alexeev ◽  
Elena Igorevna Verboloz

The article focuses on the process of intensive mixing of liquid phase in the tin during high-temperature sterilization, i.e. sterilization when temperature of the heat carrier reaches 150-160°C. It has been stated that for intensification of the thermal process during sterilization of tinned fish with liquid filling it is preferable to turn a tin from bottom to top. This operation helps to increase the driving power of the process and to shorten warming time. Besides, high-temperature sterilization carried out according to experimental modes, where the number of tin turnovers is calculated, greatly shortens processing time and improves quality of the product. In this case there is no superheating, all tins are evenly heated. The study results will contribute to equipment modernization and to preserving valuable food qualities.


2016 ◽  
pp. 120-127
Author(s):  
Dinh Toan Nguyen

Background: Dementia after stroke, particularly subacute period is often overlooked. Today the quality of human life is increasingly high, finding scales that have high value for detection of dementia in patients with stroke is increasingly interested. MoCA test is high sensitivity with mild dementia and identify more abnormalities of awareness caused by vascular, but MoCA have not been studied much in Vietnam. Objective: Assessing MoCA test in subacute stroke patients and compare MoCA versus MMSE in these patients. Subjects: 90 patients with subacute stroke period, these people are being treated at Department of cardiovascular internal medicine at Hue Central Hospital, from 7/2014 - 7/2015. Methods: cross-sectional description and analysis. Results: The mean age is 65.57 ± 13.38, accounting for 54.4% male and 45.6% female. Age, duration of illness has weak correlation with MoCA. The risk factors: hypertension, stroke ischemic transient, alcoholism, smoking, heart disease, diabetes, dyslipidemia related no statistical significance with MoCA. The proportion of dementia in subacute stroke according MoCA is 82.2%. The concordance between MoCA and MMSE was good (kappa = 0.684). Using DSM-IV criteria as the gold standard we found MoCA more valuable in the dementia diagnosis than MMSE (AUC 0.864 versus 0.774, p <0.05). Conclusion: The rate of dementia in stroke subacute period according MoCA is quite high. MoCA is valuable than MMSE in detecting dementia in patients with stroke subacute period, this scale is short, easy to implement so should put into using widely in clinical practice. Key words: MoCA test, subacute stroke, dementia


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