Effect of Impurity Ions and Permanent Dipoles for Device Performance of Thin-Film Electroluminescent Diodes

1997 ◽  
Vol 488 ◽  
Author(s):  
Tetsuo Tsutsui ◽  
Masayuki Yahiro ◽  
Dechun Zou
Keyword(s):  
Thin Film ◽  
Current Density ◽  
Reverse Bias ◽  
Short Circuit ◽  
Device Performance ◽  
Constant Voltage ◽  
Device Structure ◽  
Organic Layers ◽  
Impurity Ions ◽  
Ionic Impurities

AbstractDouble-layer EL diodes composed of a spin-coated Polyvinylcarbazole (PVCz) layer and a vacuum-sublimed tris-(8-hydroxyquinoline)aluminum (Alq) layer were prepared. The diodes with the same device structure but with PVCz layer with added ionic impurities were also prepared. The diodes were driven at constant voltage and allowed to stand under short-circuit or reverse bias conditions. Observations of luminance-current density-voltage relations at constant voltage driving were repeated. The decrease of both luminance and current density during constant voltage driving were observed. Both spontaneous and reverse-bias assisted recovery of device performances were observed and these degradation and recovery phenomena were discussed in terms of the movement of ionic impurities in organic layers.

scholarly journals Simulating the performance of a highly efficient CuBi2O4-based thin-film solar cell

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Adnan Hosen ◽  
Md. Suruz Mian ◽  
Sheikh Rashel Al Ahmed
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Current Density ◽  
High Efficiency ◽  
Defect Density ◽  
Cell Structure ◽  
Short Circuit ◽  
Open Circuit ◽  
Absorber Layer ◽  
Device Structure

AbstractIn this study, copper bismuth oxide (CuBi2O4) absorber-based thin film heterojunction solar cell structure consisting of Al/FTO/CdS/CuBi2O4/Ni has been proposed. The proposed solar cell device structure has been modeled and analyzed by using the solar cell capacitance simulator in one dimension (SCAPS-1D) software program. The performance of the proposed photovoltaic device is evaluated numerically by varying thickness, doping concentrations, defect density, operating temperature, back metal contact work function, series and shunt resistances. The current density–voltage behaviors at dark and under illumination are investigated. To realize the high efficiency CuBi2O4-based solar cell, the thickness, acceptor and donor densities, defect densities of different layers have been optimized. The present work reveals that the power conversion efficiency can be enhanced by increasing the absorber layer thickness. The efficiency of 26.0% with open-circuit voltage of 0.97 V, short-circuit current density of 31.61 mA/cm2, and fill-factor of 84.58% is achieved for the proposed solar cell at the optimum 2.0-μm-thick CuBi2O4 absorber layer. It is suggested that the p-type CuBi2O4 material proposed in the present study can be employed as a promising absorber layer for applications in the low cost and high efficiency thin-film solar cells.

Hg1−x−yMnxCdyTe Alloys for 1.3−1.8 μm Photodiode Applications

1986 ◽  
Vol 89 ◽  
Author(s):  
S. H. Shin ◽  
J. G. Pasko ◽  
D. S. Lo ◽  
W. E. Tennant ◽  
J. R. Anderson ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Room Temperature ◽  
Reverse Bias ◽  
Fiber Optic ◽  
Superior Performance ◽  
Device Performance ◽  
Device Structure ◽  
Cdte Substrate ◽  
P Type

AbstractHgMnCdTe/CdTe photodiodes with responsivity cutoffs of up to 1.54 pm have been fabricated by liquid phase epitaxy (LPE). The mesa device structure consists of a boron-implanted mosaic fabricated on a p-type Hg1−x−yMnxCdyTe layer grown on a CdTe substrate. A reverse breakdown voltage (VB) of 50 V and a leakage current density of 1.5 × 10−4 A/cm2 at V = −10 V was measured at room temperature (295K). A 0.75 pF capacitance was also measured under a 5 V reverse bias at room temperature. This device performance based on the quaternary HgMnCdTe shows both theoretical and practical promise of superior performance for wavelengths in the range 1.3 to 1.8 μm for fiber optic applications.

Nanoimprint Photonic Crystal Film Enhanced Light-Trapping in a-Si Thin Film Solar Cells

2011 ◽  
Vol 110-116 ◽  
pp. 497-502
Author(s):  
Wei Ping Chu ◽  
Fuh Shyang Juang ◽  
Jian Shian Lin ◽  
Tien Chai Lin ◽  
Chen Wei Kuo
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Photonic Crystals ◽  
Current Density ◽  
Light Trapping ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Thin Film Solar Cells ◽  
Uv Lamp

We utilize photonic crystals to enhanced lighttrapping in a-Si:H thin film solar cells. The photonic crystals effectively increase Haze ratio of glass and decrease reflectance of a-Si:H solar cells. Therefore, increase the photon path length to obtain maximum absorption of the absorber layer. The photonic crystals can effective in harvesting weakly absorbing photons with energies just above the band edge. We were spin coated UV glue on the glass, and then nanoimprint of photonic crystals pattern. Finally, used UV lamp was curing of UV glue on the glass. When the 45∘composite photonic crystals structures, the haze was increase to 87.9 %, resulting the short circuit current density and efficiency increasing to 13.96 mA/cm2 and 7.39 %, respectively. Because 45∘composite photonic crystals easy to focus on the point of light lead to the effect of scattering can’t achieve. So, we designs 90∘V-shaped photonic crystals structures to increase scattering. When the 90∘V-shaped photonic crystals structures, the Haze was increase to 93.9 %. Therefore, the short circuit current density and Efficiency increasing to 15.62 mA/cm2 and 8.09 %, respectively. We observed ~35 % enhancement of the short-circuit current density and ~31 % enhancement of the conversion efficiency.

Effect of dielectric/organic interface properties on the performance of the organic thin film transistors

2013 ◽  
Vol 1501 ◽  
Author(s):  
Ronak Rahimi ◽  
D. Korakakis
Keyword(s):  
Molecular Structure ◽  
Thin Film ◽  
Thin Film Transistors ◽  
Carrier Mobility ◽  
Charge Carrier Mobility ◽  
Organic Thin Film Transistors ◽  
Device Performance ◽  
Electrical Characteristics ◽  
Organic Thin Film ◽  
Organic Layers

ABSTRACTIn order to manufacture organic electronic devices with high performance, more detailed studies of the structure and the morphology of the organic materials as well as the underlying physical charge transport mechanisms are warranted. For instance, high efficiency organic thin film transistors (OTFTs) require materials with high charge carrier mobility [1, 2]. The parameters that determine the charge carrier mobility of the device include the structure of the first organic layer at the organic-dielectric interface as well as the morphology and the structural order of the other organic layers. Therefore, fundamental questions about structural properties of organic materials should be answered in order to optimize device performance [2-4].In this work, several bilayer structures of LiF/PTCDI-C8 and LiF/pentacene were prepared and their morphology and molecular structure were characterized using X-ray reflectivity (XRR) technique. In order to study the effects of the films’ structures and dielectric/organic interfacial properties on the device performance, OTFTs based on these bilayers were fabricated and characterized. It has been observed that PTCDI-C8 thin films have higher molecular packing in the LiF/PTCDI-C8 bilayer structure, which results in superior electrical characteristics for OTFTs based on this organic material. Devices with LiF/PTCDI-C8 bilayer exhibit about one order of magnitude higher output current (Ids) at a constant drain-source voltage (Vds) compared to the devices with LiF/pentacene bilayer. The observed differences in the electrical characteristics of these devices can be attributed to the effects of the dielectric/organic interface and the molecular structure of the organic layers.

scholarly journals The Effects of ZnTe:Cu Back Contact on the Performance of CdTe Nanocrystal Solar Cells with Inverted Structure

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 626 ◽  
Author(s):  
Bingchang Chen ◽  
Junhong Liu ◽  
Zexin Cai ◽  
Ao Xu ◽  
Xiaolin Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Contact Layer ◽  
Open Circuit ◽  
Band Alignment ◽  
Device Performance ◽  
Back Contact ◽  
Device Structure ◽  
Inverted Structure ◽  
Cdte Nanocrystal

CdTe nanocrystal (NC) solar cells have received much attention in recent years due to their low cost and environmentally friendly fabrication process. Nowadays, the back contact is still the key issue for further improving device performance. It is well known that, in the case of CdTe thin-film solar cells prepared with the close-spaced sublimation (CSS) method, Cu-doped CdTe can drastically decrease the series resistance of CdTe solar cells and result in high device performance. However, there are still few reports on solution-processed CdTe NC solar cells with Cu-doped back contact. In this work, ZnTe:Cu or Cu:Au back contact layer (buffer layer) was deposited on the CdTe NC thin film by thermal evaporation and devices with inverted structure of ITO/ZnO/CdSe/CdTe/ZnTe:Cu (or Cu)/Au were fabricated and investigated. It was found that, comparing to an Au or Cu:Au device, the incorporation of ZnTe:Cu as a back contact layer can improve the open circuit voltage (Voc) and fill factor (FF) due to an optimized band alignment, which results in enhanced power conversion efficiency (PCE). By carefully optimizing the treatment of the ZnTe:Cu film (altering the film thickness and annealing temperature), an excellent PCE of 6.38% was obtained, which showed a 21.06% improvement compared with a device without ZnTe:Cu layer (with a device structure of ITO/ZnO/CdSe/CdTe/Au).

Characterization of the Piezoelectric Response of Aluminum Nitride Grown by dc Magnetron Sputtering for Applications in Thin-Film Resonators

1996 ◽  
Vol 444 ◽  
Author(s):  
Rajan S. Naik ◽  
Joseph J. Lutsky ◽  
Rafael Reif ◽  
Charles G. Sodini
Keyword(s):  
Thin Film ◽  
Aluminum Nitride ◽  
Magnetron Sputtering ◽  
Parameter Extraction ◽  
Bulk Acoustic Wave ◽  
Piezoelectric Response ◽  
Device Performance ◽  
Coupling Coefficients ◽  
Dc Magnetron Sputtering ◽  
Device Structure

AbstractAluminum nitride is a promising material for use in thin-film bulk acoustic wave resonators for applications in RF bandpass filters. This paper discusses the requirements needed for a dc magnetron sputtering system to grow piezoelectrically active films with x-ray diffraction rocking curves of 3.3° on silicon substrates, 5° on aluminum substrates and oxygen concentrations of l at.%. For applications in integrated resonators, a materials characterization is insufficient in predicting the subsequent device performance. A simple acoustic device structure which allows a quick measurement of the device performance is used to extract maximum effective coupling coefficients keff2 of 0.009% at 3.4GHz and 0.002% at 2.4GHz for two different films with rocking curves of 5.7° and 9.0° respectively. This parameter extraction technique may be used to make relative comparisons between films grown under different deposition conditions.

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