scholarly journals Vertically Aligned Few-Layered Graphene-Based Non-Cryogenic Bolometer

2019 ◽  
Vol 5 (2) ◽  
pp. 23 ◽  
Author(s):  
Anil K. Yadav ◽  
Saba Mehsar Khan ◽  
Anirban Kundu ◽  
Renu Rani ◽  
Navneet Soin ◽  
...  

In this study, we report the photoresponse of vertically aligned few-layered graphene (VAG) upon infra-red (IR) irradiation at room temperature. Four probe measurements showed the current–voltage (I–V) characteristic of electrical switching during pulsed IR irradiation. The photoresponse reported here for VAG was significantly higher than that reported for carbon nanotube (CNT) samples. Our investigation shows that such a photoresponse arose solely from the bolometric effect, where the conductivity changed with temperature. The resistance magnitude of the VAGs increased ~two fold for each 6 °C increase in temperature. Also, the Thermal Coefficient of Resistance (TCR) in this region was ~11%/K, which is the highest TCR value reported for any carbon nanomaterial.

2006 ◽  
Vol 910 ◽  
Author(s):  
Andrey Kosarev ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Roberto Ambrosio

AbstractWe have fabricated and studied an un-cooled micro-bolometer with thermo-sensing layer sandwiched between two electrodes. The micro-bolometer has “bridge” configuration to provide sufficient thermo isolation of the thermo-sensing layer and is made on the surface of silicon wafer by means of surface micro-machining technique. The support layer of SiN and thermo-sensing layer of a-Ge:H,F have been deposited by low frequency PE CVD. The active area of the thermo-sensing layer is Ab=70x66 μm2. Temperature dependence of conductivity σ(T), current-voltage characteristics I(U), spectral noise density and thermal response time have been measured to characterize operation and to determine main performance characteristics. Activation energy of the thermo-sensing layer was Ea=0.34 eV providing thermal coefficient of resistance α=0.043 K-1. Pixel resistance was in the range Rb=(1÷30)x105 Ohm. Current and voltage responsivities were in the range RI=0.3÷14 AW-1 and RU=(1÷2)x105 VW-1, respectively. The value of detectivity was in the range of D*=(1÷40)x108 cmHz1/2W-1 and response time was τ=100 μs. The characteristics obtained in this micro-bolometer with sandwiched thermo-sensing layer make it promising for further development.


2015 ◽  
Vol 799-800 ◽  
pp. 153-157 ◽  
Author(s):  
Anika Zafiah Mohd Rus ◽  
Nur Munirah Abdullah ◽  
M.F.L. Abdullah ◽  
M. Izzul Faiz Idris

The conductive thin film was made based on bio-based epoxy and graphite compounded with its cross-linker (Methylene Diphenyl Diisocyanate, MDI) and further blended with disparate percentages of pretreated graphite. The preparation of this solution started by drop casting as thin films, where the thickness of thin film was set approximately ~0.1 mm. Optical microscope, Fourier transform infra-red spectroscopy (FTIR) and Ultraviolet-visible (UV-vis) spectrophotometer has been operated to diagnose Graphite/ biopolymer composites in order to have better and accurate results of this work. The current-voltage (I-V) characteristics of the composite thin film samples were measured at room temperature. This study shows the electrical conductivity was discovered and calculated by achieving conductivity of 103S/m as a prove that this thin film has the ability to conduct electricity.


Author(s):  
C. Wolpers ◽  
R. Blaschke

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.


2002 ◽  
Vol 719 ◽  
Author(s):  
Galina Khlyap

AbstractRoom-temperature electric investigations carried out in CO2-laser irradiated ZnCdHgTe epifilms revealed current-voltage and capacitance-voltage dependencies typical for the metal-semiconductor barrier structure. The epilayer surface studies had demonstrated that the cell-like relief has replaced the initial tessellated structure observed on the as-grown samples. The detailed numerical analysis of the experimental measurements and morphological investigations of the film surface showed that the boundaries of the cells formed under the laser irradiation are appeared as the regions of accumulation of derived charged defects of different type of conductivity supplying free charge carriers under the applied electric field.


Nano Research ◽  
2021 ◽  
Author(s):  
Leigang Li ◽  
Shikhar Misra ◽  
Xingyao Gao ◽  
Juncheng Liu ◽  
Han Wang ◽  
...  

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10212-10223
Author(s):  
Abhijit Rudra Paul ◽  
Bapi Dey ◽  
Sudip Suklabaidya ◽  
Syed Arshad Hussain ◽  
Swapan Majumdar

In this article, we demonstrate the design, synthesis and physico-chemical characteristics, including electrical switching behaviours of long alkoxy-appended coumarin carboxylate/carboxylic acid in thin films.


2013 ◽  
Vol 717 ◽  
pp. 113-116
Author(s):  
Sani Klinsanit ◽  
Itsara Srithanachai ◽  
Surada Ueamanapong ◽  
Sunya Khunkhao ◽  
Budsara Nararug ◽  
...  

The effect of soft X-ray irradiation to the Schottky diode properties was analyzed in this paper. The built-in voltage, leakage current, and work function of Schottky diode were investigated. The current-voltage characteristics of the Schottky diode are measured at room temperature. After irradiation at 70 keV for 55 seconds the forward current and leakage current are increase slightly. On the other hand, the built-in voltage is decrease from the initial value about 0.12 V. Consequently, this method can cause the Schottky diode has low power consumption. The results show that soft X-ray can improve the characteristics of Schottky diode.


2004 ◽  
Vol 85 (1) ◽  
pp. 115-117 ◽  
Author(s):  
Wenping Hu ◽  
Hiroshi Nakashima ◽  
Kazuaki Furukawa ◽  
Yoshiaki Kashimura ◽  
Katsuhiro Ajito ◽  
...  

1998 ◽  
Vol 536 ◽  
Author(s):  
S. B. Aldabergenova ◽  
M. Albrecht ◽  
A. A. Andreev ◽  
C. Inglefield ◽  
J. Viner ◽  
...  

AbstractWe report on strong Er3+ luminescence in the visible and infra-red regions at room temperature in amorphous GaN:Er thin films prepared by DC magnetron co-sputtering. The intensity of the Er3+ luminescence at 1.535 μm corresponding to 4I13/2 → 4I15/2 transitions is greatly enhanced after annealing at 750°C. In this material GaN crystallites have formed and embedded in the continuous amorphous matrix. The crystallites are 4 to 7 nm in diameter as analyzed by high resolution transmission electron microscopy. The absorption edge, extending three orders of magnitude in absorption coefficient in the spectral range from 0.5 to 3.5 eV, is superimposed on resonant absorption bands of Er3+ ions.The total photoluminescence spectrum consists of welldefined Er3+ luminescence peaks imposed on a broad band edge luminescence from the amorphous GaN host matrix.


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