Influence of Temperature on Graphene/ZnO Heterojunction Schottky Diode Characteristics

2021 ◽  
Vol 21 (5) ◽  
pp. 3165-3170
Author(s):  
Ashish Kumar ◽  
Arathy Varghese ◽  
Shriniwas Yadav ◽  
Mahanth Prasad ◽  
Vijay Janyani ◽  
...  
Keyword(s):  
Schottky Diode ◽  
Ideality Factor ◽  
Indium Tin Oxide ◽  
Flexible Substrate ◽  
Copper Substrate ◽  
Electrical Characterization ◽  
Chemical Vapor ◽  
Energy Storage Devices ◽  
Influence Of Temperature On ◽  
Cell Energy

The paper reports development of graphene/ZnO heterojunction Schottky diode structure and its structural and electrical characterization. Graphene is grown on copper substrate using chemical vapor deposition (CVD) and transferred on flexible substrate (indium Tin Oxide coated PET). The grown thin layer is characterized using scanning electron microscopy and Raman spectroscopy which confirm uniformity and high-quality graphene layer. The sputtered ZnO is deposited and characterized which confirms c-axis (002) orientation and uniform growth of ZnO film. Silver (Ag) as a top electrode has been deposited and I–V measurement has been done. The effect of operating temperature (300 K to 425 K) on I–V characteristics of the fabricated structure has been measured experimentally. The other diode parameters such as ideality factor and effective barrier height have been derived. The reliability of the heterojunction synthesized is proved by the diode ideality factor of 1.03 attained at 425 K. The excellent C–V characteristics (capacitance of 48pF) of the device prove that the device is an excellent candidate for application as supercapacitors. The fabricated structure can be utilized as an ultraviolet photodetector, solar cell, energy storage devices, etc.

scholarly journals CVD-Graphene-Based Flexible, Thermoelectrochromic Sensor

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Adam Januszko ◽  
Agnieszka Iwan ◽  
Stanislaw Maleczek ◽  
Wojciech Przybyl ◽  
Iwona Pasternak ◽  
...  
Keyword(s):  
Graphene Layer ◽  
Flexible Substrate ◽  
Copper Substrate ◽  
Main Idea ◽  
Chemical Vapor ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Mechanical Destruction ◽  
Graphene Layers ◽  
Energy Current

The main idea behind this work was demonstrated in a form of a new thermoelectrochromic sensor on a flexible substrate using graphene as an electrically reconfigurable thermal medium (TEChrom™). Our approach relies on electromodulation of thermal properties of graphene on poly(ethylene terephthalate) (PET) via mechanical destruction of a graphene layer. Graphene applied in this work was obtained by chemical vapor deposition (CVD) technique on copper substrate and characterized by Raman and scanning tunneling spectroscopy. Electrical parameters of graphene were evaluated by the van der Pauw method on the transferred graphene layers onto SiO2 substrates by electrochemical delamination method. Two configurations of architecture of sensors, without and with the thermochromic layer, were investigated, taking into account the increase of voltage from 0 to 50 V and were observed by thermographic camera to define heat energy. Current-voltage characteristics obtained for the sensor with damaged graphene layer are linear, and the resistivity is independent from the current applied. The device investigated under 1000 W/m2 exhibited rise of resistivity along with increased temperature. Flexible thermoelectrochromic device with graphene presented here can be widely used as a sensor for both the military and civil monitoring.

scholarly journals Fabrication of Piezoelectric ZnO Nanowires Energy Harvester on Flexible Substrate Coated with Various Seed Layer Structures

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1433
Author(s):  
Taoufik Slimani Tlemcani ◽  
Camille Justeau ◽  
Kevin Nadaud ◽  
Daniel Alquier ◽  
Guylaine Poulin-Vittrant
Keyword(s):  
Seed Layer ◽  
Layer Structure ◽  
Mechanical Energy ◽  
Flexible Substrate ◽  
Average Power ◽  
Electrical Characterization ◽  
Zno Nanowires ◽  
Device Structure ◽  
Layer Structures ◽  
Electrical Output

Flexible piezoelectric nanogenerators (PENGs) are very attractive for mechanical energy harvesting due to their high potential for realizing self-powered sensors and low-power electronics. In this paper, a PENG that is based on zinc oxide (ZnO) nanowires (NWs) is fabricated on flexible and transparent Polydimethylsiloxane (PDMS) substrate. The ZnO NWs were deposited on two different seed layer structures, i.e., gold (Au)/ZnO and tin-doped indium-oxide (ITO)/ZnO, using hydrothermal synthesis. Along with the structural and morphological analyses of ZnO NWs, the electrical characterization was also investigated for ZnO NWs-based flexible PENGs. In order to evaluate the suitability of the PENG device structure, the electrical output performance was studied. By applying a periodic mechanical force of 3 N, the ZnO NWs-based flexible PENG generated a maximum root mean square (RMS) voltage and average power of 2.7 V and 64 nW, respectively. Moreover, the comparison between the fabricated device performances shows that a higher electrical output can be obtained when ITO/ZnO seed layer structure is adopted. The proposed ZnO NWs-based PENG structure can provide a flexible and cost-effective device for supplying portable electronics.

scholarly journals PANI-Based Wearable Electrochemical Sensor for pH Sweat Monitoring

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 169
Author(s):  
Francesca Mazzara ◽  
Bernardo Patella ◽  
Chiara D’Agostino ◽  
Maria Giuseppina Bruno ◽  
Sonia Carbone ◽  
...  
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Electrochemical Sensors ◽  
Flexible Substrate ◽  
Sensor Performance ◽  
Non Invasive ◽  
Static Contact ◽  
Sweat Sample ◽  
Constant Potential ◽  
Interference Tests

Nowadays, we are assisting in the exceptional growth in research relating to the development of wearable devices for sweat analysis. Sweat is a biofluid that contains useful health information and allows a non-invasive, continuous and comfortable collection. For this reason, it is an excellent biofluid for the detection of different analytes. In this work, electrochemical sensors based on polyaniline thin films deposited on the flexible substrate polyethylene terephthalate coated with indium tin oxide were studied. Polyaniline thin films were abstained by the potentiostatic deposition technique, applying a potential of +2 V vs. SCE for 90 s. To improve the sensor performance, the electronic substrate was modified with reduced graphene oxide, obtained at a constant potential of −0.8 V vs. SCE for 200 s, and then polyaniline thin films were electrodeposited on top of the as-deposited substrate. All samples were characterized by XRD, SEM, EDS, static contact angle and FT-IR/ATR analysis to correlate the physical-chemical features with the performance of the sensors. The obtained electrodes were tested as pH sensors in the range from 2 to 8, showing good behavior, with a sensitivity of 62.3 mV/pH, very close to a Nernstian response, and a reproducibility of 3.8%. Interference tests, in the presence of competing ions, aimed to verify the selectivity, were also performed. Finally, a real sweat sample was collected, and the sweat pH was quantified with both the proposed sensor and a commercial pH meter, showing an excellent concordance.

Nano-Crystalline Diamond Films Deposited on Copper Substrate by MPCVD Method

2011 ◽  
Vol 117-119 ◽  
pp. 1310-1314
Author(s):  
Xing Rui Li ◽  
Xin Wei Shi ◽  
Ning Yao ◽  
Xin Chang Wang
Keyword(s):  
Diamond Film ◽  
Deposition Time ◽  
Microwave Plasma ◽  
Copper Substrate ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Annealing Process ◽  
Adhesive Properties ◽  
Plasma Chemical Vapor Deposition ◽  
Nano Crystalline

Nano-crystalline diamond (NCD) films with good adhesion were deposited on flexible copper substrate with Ni interlayer by Microwave Plasma Chemical Vapor Deposition (MPCVD). In this paper, two-stage method was used to improve the adhesion between the copper substrates and the diamond films. The effect of deposition time of the first stage on the morphology, crystal structure, non-diamond phase and adhesive properties of diamond films was investigated. The performance and structure of the diamond films were studied by Scanning Electron Microscope (SEM), Raman Spectroscopy (Raman) and X-Ray Diffraction (XRD). The results showed that the films were nano-crystalline diamond films positively. Impress method was used to examine the adhesion between diamond film and the substrate. When deposition time is 1.5h, the adhesion between diamond film and the copper substrate is better than the others. When it was 2.5h or longer, because the graphite layers existed as intermediate, the adherence between the diamond films and copper substrates was very poor. Therefore, the diamond films were easily peeled off from the substrates. Otherwise, the second stage called annealing process after the deposition played an important role to the adhesion. The films would be easily peeled off by curling without the annealing process.

The electrical characterization of Ag/PTCDA/PEDOT:PSS/p-Si Schottky diode by current–voltage characteristics

2013 ◽  
Vol 415 ◽  
pp. 77-81 ◽  
Author(s):  
Muhammad Tahir ◽  
Muhammad Hassan Sayyad ◽  
Fazal Wahab ◽  
Dil Nawaz Khan ◽  
Fakhra Aziz
Keyword(s):  
Schottky Diode ◽  
Electrical Characterization ◽  
Current Voltage ◽  
Current Voltage Characteristics

Crystallinity and Schottky diode characteristics of GaAs grown on Si by metalorganic chemical vapor deposition

1990 ◽  
Vol 67 (11) ◽  
pp. 6908-6913 ◽  
Author(s):  
T. Egawa ◽  
S. Nozaki ◽  
N. Noto ◽  
T. Soga ◽  
T. Jimbo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Schottky Diode ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Metalorganic Chemical

scholarly journals Low-Temperature Chemical Vapor Deposition Growth of MoS2 Nanodots and Their Raman and Photoluminescence Profiles

2021 ◽  
Vol 3 ◽  
Author(s):  
Larionette P. L. Mawlong ◽  
Ravi K. Biroju ◽  
P. K. Giri
Keyword(s):  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Flexible Substrate ◽  
Chemical Vapor ◽  
Structural Defects ◽  
Chemical Vapor Deposition Growth ◽  
Raman Modes

We report on the growth of an ordered array of MoS2 nanodots (lateral sizes in the range of ∼100–250 nm) by a thermal chemical vapor deposition (CVD) method directly onto SiO2 substrates at a relatively low substrate temperature (510–560°C). The temperature-dependent growth and evolution of MoS2 nanodots and the local environment of sulfur-induced structural defects and impurities were systematically investigated by field emission scanning electron microscopy, micro-Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques. At the substrate temperature of 560°C, we observed mostly few-layer MoS2, and at 510°C, multilayer MoS2 growth, as confirmed from the Raman line shape analysis. With reduced substrate temperature, the density of MoS2 nanodots decreases, and layer thickness increases. Raman studies show characteristic Raman modes of the crystalline MoS2 layer, along with two new Raman modes centered at ∼346 and ∼361 cm−1, which are associated with MoO2 and MoO3 phases, respectively. Room temperature photoluminescence (PL) studies revealed strong visible PL from MoS2 layers, which is strongly blue-shifted from the bulk MoS2 flakes. The strong visible emission centered at ∼ 658 nm signifies a free excitonic transition in the direct gap of single-layer MoS2. Position-dependent PL profiles show excellent uniformity of the MoS2 layers for samples grown at 540 and 560°C. These results are significant for the low-temperature CVD growth of a few-layer MoS2 dots with direct bandgap photoluminescence on a flexible substrate.

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