Current Status of thin film HgCdTe: Relationship of Structure and Chemistry to Device Application

1985 ◽  
Vol 47 ◽  
Author(s):  
E. Krikorian
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Device Fabrication ◽  
Film Deposition ◽  
Current Status ◽  
Film Properties ◽  
High Quality ◽  
Device Application

ABSTRACTThis paper addresses the current status of thin film HgCdTe and limitations in the currently achievable thin film properties. The emphasis is placed on Hg1−xCdxTe since this material is presently most seriously considered for infrared devices and particularly resistant to high quality film preparation due to large elemental vapor pressure differences. The current status of thin film HgCdTe is reviewed and the various thin film deposition techniques utilized to prepare HgCdTe thin films are compared. Finally, results are reviewed which still support the claim.that the less investigated technique of bias-sputtering, modified to accommodate deposition in a high partial pressure background of Hg vapor, can yield structurally high quality Hg1−xCdxTe films with device-worthy properties. Significant is the fact that the deposition process still provides the simple and systematic control over all relevant film properties without post-deposition treatment. Such control is required to achieve the desired material for device application. As is also reviewed here, this work was one of the first to demonstrate the ability to use low cost foreign substrates for HgCdTe thin film device fabrication.

scholarly journals Bias Stress in Organic Thin-Film Transistors Towards Low-Cost Flexible Gas Sensors

2021 ◽  
Vol 16 (2) ◽  
pp. 1-11
Author(s):  
José Enrique Eirez Izquierdo ◽  
José Diogo da Silva Oliveira ◽  
Vinicius Augusto Machado Nogueira ◽  
Dennis Cabrera García ◽  
Marco Roberto Cavallari ◽  
...  
Keyword(s):  
Thin Film ◽  
Flexible Electronics ◽  
Thin Film Transistors ◽  
Low Cost ◽  
Thin Film Deposition ◽  
Dielectric Surface ◽  
Organic Thin Film Transistors ◽  
Film Deposition ◽  
Organic Thin Film ◽  
Bias Stress

This work is focused on the bias stress (BS) effects in Organic Thin-Film Transistors (OTFTs) from poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT-C14) on both highly-doped Si and glass substrates. While the former had a thermally-grown SiO2 dielectric, the latter demanded an alternative dielectric that should be capable to withstand bottom contact lithography, as well as semiconducting thin-film deposition. In addition, it should represent one more step towards flexible electronics. In order to do that, poly(4-vinylphenol) (PVP) was blended to poly(melamine-co-formaldehyde) methylated (PMF). OTFTs on glass with a cross-linked polymer dielectric had a charge carrier mobility (μ) of 4.0x10-4 cm2/Vs, threshold voltage (VT) of 18 V, current modulation (ION/OFF) higher than 1x102, and subthreshold slope (SS) of -7.7 V/dec. A negative BS shifted VT towards negative values and produced an increase in ION/OFF. A positive BS, on the other hand, produced the opposite effect only for OTFTs on Si. This is believed to be due to a higher trapping at the PVP:PMF interface with PBTTT-C14. Modeling the device current along time by a stretched exponential provided shorter time constants of ca. 105 s and higher exponents of 0.7–0.9 for devices on glass. Due to the presence of increased BS effects, the application of organic TFTs based on PVP:PMF as flexible sensors will require compensating circuits, lower voltages or less measurements in time. Alternatively, BS effects could be reduced by a dielectric surface treatment.

Spray Pyrolysis Thin Film Deposition Technique for Micro-Sensors and Devices

2020 ◽  
pp. 178-202
Author(s):  
Monoj Kumar Singha ◽  
Vineet Rojwal
Keyword(s):  
Thin Film ◽  
Spray Pyrolysis ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Deposition Technique ◽  
Uv Photodetector ◽  
Spray Process ◽  
Spray Pyrolysis Deposition ◽  
Deposition Techniques

Thin film is used for sensing and electronic devices applications. Various techniques are used for thin film deposition. This chapter presents the Spray pyrolysis deposition technique used for the growth of thin films sensing and device material. Spray pyrolysis is an inexpensive method to grow good crystalline thin film compared to other thin film deposition techniques. The chapter gives an overview of the spray process used for thin film deposition. Basic setup for this process is explained. Parameters affecting the deposition process is explained, as are the various spray methods. Finally, some examples of spray pyrolysis in different applications like a gas sensor, UV photodetector, solar cell, photocatalysis, and supercapacitor are discussed.

The Simulation of Polycrystalline Silicon Thin Film Deposition in PECVD System

2011 ◽  
Vol 189-193 ◽  
pp. 2032-2036 ◽  
Author(s):  
Zhi Jian Wang ◽  
Xiao Feng Shang
Keyword(s):  
Thin Film ◽  
Deposition Rate ◽  
Polycrystalline Silicon ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Main Reaction ◽  
Silicon Thin Film ◽  
Simulation Results

Taking Silicon tetrachloride (SiCl4) and hydrogen (H2) as the reaction gas, by the method of plasma-enhanced chemical vapor deposition (PECVD), this paper simulates the deposition process of polycrystalline silicon thin film on the glass substrates in the software FLUENT. Three dimensional physical model and mathematics model of the simulated area are established. The reaction mechanism including main reaction equation and several side equations is given during the simulation process. The simulation results predict the velocity field, temperature distribution, and concentration profiles in the PECVD reactor. The simulation results show that the deposition rate of silicon distribution is even along the circumference direction, and gradually reduced along the radius direction. The deposition rate is about 0.005kg/(m2•s) at the center. The simulated result is basically consistent with the practical one. It means that numerical simulation method to predict deposition process is feasible and the results are reliable in PECVD system.

scholarly journals A review on Spray pyrolysis deposited CZTS thin films for solar cell applications

2021 ◽  
Vol 23 (09) ◽  
pp. 1196-1206
Author(s):  
C.S.A. Raj ◽  
◽  
S. Sebastian ◽  
Susai Rajendran ◽  
◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Solar Cell ◽  
Spray Pyrolysis ◽  
Low Cost ◽  
Thin Film Deposition ◽  
Research Area ◽  
Film Deposition ◽  
Deposition Technique ◽  
Czts Thin Films

Cu2ZnSnS4 generally abridged as CZTS is a potential material for economical thin film solar cells, due to its appropriate band gap energy of around 1.5 eV and great absorption coefficient of above 104 cm-1. All the constituents of this material are plentiful in the earth’s crust, and they are non-hazardous making it an elegant alternative. Subsequent to the early achievement of the CZTS based solar cell with its light to electrical conversion efficiency of 0.6%, significant advancement in this research area has been attained, particularly in the last seven years. Currently, the conversion effectiveness of the CZTS thin film solar cell has enhanced to 24%. More than 500 papers on CZTS have been available and the greater part of these converses the preparation of CZTS thin films by diverse methods. Until now, many physical and chemical methods have been engaged for preparing CZTS thin films. Amongst them, spray pyrolysis is a flexible deposition technique. Spray pyrolysis is a simple deposition technique that finds use in widespread areas of thin film deposition research. This method is appropriate for depositing good quality films with low cost, clean deposition, and simplicity and flexibility in the manufacturing design. This script, reviews the synthesis of CZTS semiconductor thin films deposited by spray pyrolysis. This analysis initiates with a portrayal of the spray pyrolysis system, and then establish the CZTS and preparation of the CZTS precursor for coating. A review of spray pyrolysis of CZTS thin films are discussed in detail. To conclude, we present perspectives for advancements in spray pyrolysis for a CZTS based solar cell absorber layer.

scholarly journals Fabrication and Characterization of a Metallic–Dielectric Nanorod Array by Nanosphere Lithography for Plasmonic Sensing Application

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1691 ◽  
Author(s):  
Yuan-Fong Chou Chau ◽  
Kuan-Hung Chen ◽  
Hai-Pang Chiang ◽  
Chee Ming Lim ◽  
Hung Ji Huang ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Cost ◽  
Three Dimensional ◽  
Nanosphere Lithography ◽  
Thin Film Deposition ◽  
Nanorod Array ◽  
Film Deposition ◽  
Refractive Index Sensor ◽  
Plasmonic Sensor ◽  
Three Dimensional Finite Element

In this paper, a periodic metallic–dielectric nanorod array which consists of Si nanorods coated with 30 nm Ag thin film set in a hexagonal configuration is fabricated and characterized. The fabrication procedure is performed by using nanosphere lithography with reactive ion etching, followed by Ag thin-film deposition. The mechanism of the surface and gap plasmon modes supported by the fabricated structure is numerically demonstrated by the three-dimensional finite element method. The measured and simulated absorptance spectra are observed to have a same trend and a qualitative fit. Our fabricated plasmonic sensor shows an average sensitivity of 340.0 nm/RIU when applied to a refractive index sensor ranging from 1.0 to 1.6. The proposed substrates provide a practical plasmonic nanorod-based sensing platform, and the fabrication methods used are technically effective and low-cost.

Low-Cost Sputtering Process for Carbon Nanotubes Synthesis

2019 ◽  
Vol 891 ◽  
pp. 195-199
Author(s):  
Theerapol Thurakitseree ◽  
Chupong Pakpum
Keyword(s):  
Carbon Nanotubes ◽  
Low Cost ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Synthesis Process ◽  
Metal Thin Films ◽  
Si Substrates ◽  
Custom Made

According to their wonderful properties, carbon nanotubes (CNTs) have been well known for decades. The synthesis process and catalyst deposition method have also drawn attention to control the nanotube structure and properties. Sputtering method is then one promising option to grow the nanotubes in mass production. This method is, however, still costly. Here, we have presented a simple low-cost custom-made DC magnetron sputtering for catalyst thin film deposition. Three different metal thin films (Fe, Ni, Cu) deposited on Si substrates have been employed to investigate nanotube production. Prior to deposition of the catalysts, Al was used as supporting layer. (Al/Fe, Al/Ni, Al/Cu). CNTs were grown by chemical vapor deposition process at 800°C. Ethanol was preliminary used as a carbon source. It was found that CNTs could be successfully grown from only Al/Ni catalysts in our system with the diameter of approximately 200 nm, where the rest of samples were not observed. In addition, vertical-aligned CNTs with the thickness of about 10 μm could be obtained when acetylene was replaced instead of ethanol with reducing partial pressure of the feedstock. A large D-band at 1338 cm-1 with broader G-band at 1582 cm-1 from Raman spectra give a rise to multi layers growth of sp2 carbon walls. Such dimension suggests that it is the characteristic of multi-walled carbon nanotubes.

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