scholarly journals Reduced Graphene Oxide Inserted into PEDOT:PSS Layer to Enhance the Electrical Behaviour of Light-Emitting Diodes

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 645
Author(s):  
Fernando Rodríguez-Mas ◽  
Juan Carlos Ferrer ◽  
José Luis Alonso ◽  
Susana Fernández de Ávila ◽  
David Valiente
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Indium Tin Oxide ◽  
Cadmium Sulphide ◽  
Energy Bands ◽  
Layer Sequence ◽  
Cds Nanocrystals ◽  
Reduced Graphene ◽  
Hole Transporting

In this study, poly(9-vinylcarbazole) (PVK)-based LEDs doped with reduced graphene oxide (rGO) and cadmium sulphide (CdS) nanocrystals were fabricated by spin-coating. The hybrid LED structure was a layer sequence of glass/indium tin oxide (ITO)/PEDOT:PSS|rGO/PVK/Al. rGO was included in the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) layer due to its energy bands being close to PEDOT:PSS bands, and the possibility of using water for dispersing both polymer and flakes. Optical properties such as photoluminescence and UV-Vis absorption were not affected by the addition of rGO to the PEDOT:PSS solution. However, PVK-based LEDs with rGO showed increased current density compared to those without rGO in the hole transporting layer. Higher electroluminescence intensities were observed for rGO-enriched LEDs, although the shape of the spectrum was not modified. LEDs including CdS nanocrystals in the poly(9-vinylcarbazole) emissive layer did not show such dependence on the rGO presence. Though the addition of rGO to PEDOT:PSS still produces a slightly higher current density in CdS doped LEDs, this growth is no longer proportional to the rGO load.

scholarly journals Electrochemical Impedance Characterization of Cell Growth on Reduced Graphene Oxide–Gold Nanoparticles Electrodeposited on Indium Tin Oxide Electrodes

2019 ◽  
Vol 9 (2) ◽  
pp. 326 ◽  
Author(s):  
Somasekhar Chinnadayyala ◽  
Jinsoo Park ◽  
Yonghyun Choi ◽  
Jae-Hee Han ◽  
Ajay Yagati ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Cell Growth ◽  
Reduced Graphene Oxide ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Electrochemical Impedance ◽  
Hek293 Cells ◽  
Ito Electrode ◽  
Reduced Graphene

The improved binding ability of graphene–nanoparticle composites to proteins or molecules can be utilized to develop new cell-based assays. In this study, we fabricated reduced graphene oxide–gold nanoparticles (rGO-AuNP) electrodeposited onto a transparent indium tin oxide (ITO) electrode and investigated the feasibility of the electrochemical impedance monitoring of cell growth. The electrodeposition of rGO–AuNP on the ITO was optically and electrochemically characterized in comparison to bare, rGO-, and AuNP-deposited electrodes. The cell growth on the rGO–AuNP/ITO electrode was analyzed via electrochemical impedance measurement together with the microscopic observation of HEK293 cells transfected with a green fluorescent protein expression vector. The results showed that rGO–AuNP was biocompatible and induced an increase in cell adherence to the electrode when compared to the bare, AuNP-, or rGO-deposited ITO electrode. At 54 h cultivation, the average and standard deviation of the saturated normalized impedance magnitude of the rGO–AuNP/ITO electrode was 3.44 ± 0.16, while the value of the bare, AuNP-, and rGO-deposited ITO electrode was 2.48 ± 0.15, 2.61 ± 0.18, and 3.01 ± 0.25, respectively. The higher saturated value of the cell impedance indicates that the impedimetric cell-based assay has a broader measurement range. Thus, the rGO–AuNP/ITO electrode can be utilized for label-free and real-time impedimetric cell-based assays with wider dynamic range.

Simplified Synthesis of 3D Flexible Reduced Graphene Oxide-Wrapped NiCo2O4 Nanowires for High-Performance Supercapacitor

2018 ◽  
Vol 10 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Chao Pan ◽  
Hongyu Sun ◽  
Jingyi Gao ◽  
Yucai Hu ◽  
Jing Wang
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Current Density ◽  
Three Dimensional ◽  
Simple Method ◽  
X Ray ◽  
Reduced Graphene

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

Facile Synthesis and Performance of Reduced Graphene Oxide/Cobalt Oxide Composite for Supercapacitor

2013 ◽  
Vol 785-786 ◽  
pp. 779-782
Author(s):  
Hong Juan Wang ◽  
Dong Zhou ◽  
Feng Peng ◽  
Hao Yu
Keyword(s):  
Graphene Oxide ◽  
Specific Capacitance ◽  
Reduced Graphene Oxide ◽  
Cobalt Oxide ◽  
Current Density ◽  
Chemical Precipitation ◽  
Discharge Performance ◽  
Reduced Graphene ◽  
Subsequent Calcination ◽  
And Performance

A series of reduced graphene oxide/cobalt oxide composites (Co3O4/rGO)were fabricated via a chemical precipitation approach and subsequent calcination in Ar atmosphere. Experimental results show that Co3O4/rGO composite with 86 wt% of Co3O4 loading exhibits the optimum specific capacitance of 240 F g-1 in 6.0 M KOH electrolyte at the current density of 0.8 A g-1, excellent quick charge-discharge performance and outstanding cyclic stability with 2.3% of its specific capacitance increase after 2400 cycles at the current density of 8 A g-1 in GCD test, exhibiting significant potential of Co3O4 /rGO composite in the application of supercapacitors.

scholarly journals Formation and Characterization of Copper Nanocube-Decorated Reduced Graphene Oxide Film

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
M. Z. H. Khan ◽  
M. A. Rahman ◽  
P. Yasmin ◽  
F. K. Tareq ◽  
N. Yuta ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Indium Tin Oxide ◽  
Chemical Reduction ◽  
Device Fabrication ◽  
Simple Method ◽  
Force Microscopy ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
The Individual

In this study, we present a new approach for the formation and deposition of Cu nanocube-decorated reduced graphene oxide (rGO-CuNCs) nanosheet on indium tin oxide (ITO) electrode using very simple method. Cubic Cu nanocrystals have been successfully fabricated on rGO by a chemical reduction method at low temperature. The morphologies of the synthesized materials were characterized by ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The as-formed CuNCs were found to be homogeneously and uniformly decorated on rGO nanosheets. We demonstrated that the individual rGO sheets can be readily reduced and decorated with CuNCs under a mild condition using L-ascorbic acid (L-AA). Such novel ITO/rGO-CuNCs represent promising platform for future device fabrication and electrocatalytic applications.

scholarly journals Chemiresistive sensors based on Dodecyl benzene Sulfonic acid doped Polypyrrole and Reduced Graphene Oxide for nitrogen oxides

2021 ◽  
Vol 1204 (1) ◽  
pp. 012004
Author(s):  
Djamil Guettiche ◽  
Ahmed Mekki ◽  
Tighilt Fatma Zohra ◽  
Noureddine Ramdani ◽  
Rachid Mahmoud
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Indium Tin Oxide ◽  
Sulfonic Acid ◽  
Flexible Substrate ◽  
Structural Data ◽  
Strong Interactions ◽  
Benzene Sulfonic Acid ◽  
Reduced Graphene ◽  
Dodecyl Benzene Sulfonic Acid

Abstract A new series of polypyrrole doped with n-dodecylbenzene sulphonic acid/reduced graphene oxide (PPy-DBSA/rGO) nanocomposite was electrodeposited on Indium tin oxide coated Polyethylene terephthalate (ITO/PET) flexible substrate by electrochemical route using the chronoamperometric technique. As-prepared for testing of chemiresistive properties against the detection of nitrogen dioxide (NO2) vapors at room temperature. The sensitivity and reactivity of the composite toward NO2 was evaluated. The recorded morphological and structural data confirmed that the PPy-DBSA/rGO forms a homogeneous nanocomposite. The optimal NO2 sensing properties have been revealed by the PPy-DBSA/rGO in terms of response (43%), response time (30.25 s), the detection limit (1ppm), and reproducibility. Furthermore, Results showed that the doped by sulfonic acid improved both the sensitivity and the reactivity of our produced nanocomposite toward NO2. Due to the strong interactions between the NO2 gas molecules and the rGO was dramatically enhanced the electronic properties of these nanocomposites. These striking characteristics of the newly developed nanocomposites make them very suitable to be used as NO2 gas sensor.

scholarly journals Improved Hole Injection in Bulk Heterojunction (BHJ) Hybrid Solar Cells by Applying a Thermally Reduced Graphene Oxide Buffer Layer

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Alfian F. Madsuha ◽  
Chuyen Van Pham ◽  
Michael Eck ◽  
Martin Neukom ◽  
Michael Krueger
Keyword(s):  
Graphene Oxide ◽  
Solar Cells ◽  
Reduced Graphene Oxide ◽  
Indium Tin Oxide ◽  
Hole Transport ◽  
Band Alignment ◽  
Hybrid Solar Cells ◽  
Simple Method ◽  
Reduced Graphene ◽  
Charge Extraction

In this work, the utilization of graphene oxide (GO), reduced graphene oxide (rGO), and carbon nanotube (CNT) thin films as hole transport and electron-blocking layers in polymer/nanocrystal hybrid solar cells is demonstrated. A simple method has been used to modify the anode of hybrid solar cells by depositing these two solution-processable nanocarbon materials between poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) and transparent indium tin oxide (ITO) layers. Upon the use of an rGO interlayer, we found a substantial improvement in power conversion efficiency (PCE) from 2.5% to 3.2% due to a decrease in series resistance (Rs). This decrease has been obtained by a careful tuning of the reduction degree of rGO, inducing optimization of the energy band alignment at the solar cell anode. In addition, charge extraction by linearly increasing voltage (CELIV) measurements show an increase in light-induced charge extraction of ca. 50%. Finally, the utilization of rGO as replacement for PEDOT:PSS is also presented. The findings reported in this work demonstrate the excellent potential of rGO as an efficient hole transport material in hybrid solar cells.

2D/2D vanadyl phosphate (VP) on reduced graphene oxide as a hole transporting layer for efficient organic solar cells

2018 ◽  
Vol 59 ◽  
pp. 92-98 ◽  
Author(s):  
Ye-Jin Jeon ◽  
Jin-Mun Yun ◽  
Minji Kang ◽  
Sehyun Lee ◽  
Yen-Sook Jung ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solar Cells ◽  
Reduced Graphene Oxide ◽  
Organic Solar Cells ◽  
Vanadyl Phosphate ◽  
Reduced Graphene ◽  
Hole Transporting
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