Study of the Defect Levels and Interface Properties of CdTe and CdS Polycrystalline Thin Films

1991 ◽  
Vol 238 ◽  
Author(s):  
F. Abou-Elfotouh ◽  
S. Ashour ◽  
S. A. Alkuhaimi ◽  
J. Zhang ◽  
D. J. Dunlavy ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Deep Trap ◽  
Cdte Film ◽  
Interface States ◽  
Polycrystalline Thin Films ◽  
Deviation From Stoichiometry ◽  
Electrochemically Deposited ◽  
Defect Levels ◽  
P Type

ABSTRACTThe properties (electrical and structural) and the defect levels dominating cadmium telluride (CdTe) films prepared by radio frequency (rf) planar magnetron sputtering, and electrochemical deposition have been determined and compared. The properties of the deposited CdTe film and the behavior of its interface with cadmium sulfide (CdS) depend strongly on the method of depositing the CdTe film, and on postdeposition heat treatments. These treatments determine various parameters crucial to the device performance, including the type and concentration of the dominant defects, interface states, and deep trap levels. Photoluminescence (PL) emission from p-type CdTe polycrystalline thin films and single crystals is reported at low temperatures (9–50 K) as well as at room temperature. The room temperature PL peak at 1.58 eV due to band-to-band recombination was observed for the first time in polycrystalline thin films. The peak location of the exciton emission is indicative of the structure perfection of the film, which is also related to the deviation from stoichiometry. The as-grown polycrystalline films are composed of a close-packed array of preferentially oriented (the [100], [110], and [111] axes aligned perpendicular to the substrate) single-crystal grains of a size in the range of 0.25–2.0 μm for the electrochemically deposited films (E-film) and 0.3–4.0 μm for rf sputtered material (rf-film). The resistivity of the heat treated E-film was substantially lower than that of the rf-film (ρ = 1.0–5.0 and 300–500 Ωcm). The performance of the CdS/(E-CdTe) devices is limited by deep levels, while the performance of die rf-CdTe device is affected by a high density of interface states.

Record Conductivity for P-Type Transparent Conductors in Polycrystalline Thin Films of a Sulfide-Fluoride

2008 ◽  
Vol 1101 ◽  
Author(s):  
Jesse Frantz ◽  
Jasbinder S. Sanghera ◽  
Syed B. Qadri ◽  
Ishwar D. Aggarwal
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Protective Layer ◽  
Rf Magnetron Sputtering ◽  
Transparent Conductors ◽  
Cubic Phase ◽  
Face Centered Cubic ◽  
Polycrystalline Thin Films ◽  
Sulfur Fluoride ◽  
P Type

AbstractBarium copper sulfur fluoride thin films with a face-centered cubic phase in the Fm3m space group were synthesized via RF magnetron sputtering. The results of a detailed optical and electronic characterization of the films are presented. As-deposited, they exhibit degenerate p-type conductivity at room temperature of approximately 260 S/cm – higher than that of any previously reported p-TC. Their conductivity after post-deposition processing increases to as high as 800 S/cm. The films exhibit bandgaps ranging from 1.45-1.75 eV. They are typically deposited with a substrate temperature between room temperature and 100°C, making them suitable for deposition on plastic as well as glass or crystalline substrates. It was found that a silica protective layer reduces degradation in film transparency that is caused by exposure to air.

scholarly journals Direct measurement of the thermoelectric properties of electrochemically deposited Bi2Te3 thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jose Recatala-Gomez ◽  
Pawan Kumar ◽  
Ady Suwardi ◽  
Anas Abutaha ◽  
Iris Nandhakumar ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermoelectric Properties ◽  
Bismuth Telluride ◽  
Indium Tin Oxide ◽  
Seed Layer ◽  
Room Temperature ◽  
Low Cost ◽  
Temperature Dependent ◽  
Temperature Heat ◽  
Electrochemically Deposited

Abstract The best known thermoelectric material for near room temperature heat-to-electricity conversion is bismuth telluride. Amongst the possible fabrication techniques, electrodeposition has attracted attention due to its simplicity and low cost. However, the measurement of the thermoelectric properties of electrodeposited films is challenging because of the conducting seed layer underneath the film. Here, we develop a method to directly measure the thermoelectric properties of electrodeposited bismuth telluride thin films, grown on indium tin oxide. Using this technique, the temperature dependent thermoelectric properties (Seebeck coefficient and electrical conductivity) of electrodeposited thin films have been measured down to 100 K. A parallel resistor model is employed to discern the signal of the film from the signal of the seed layer and the data are carefully analysed and contextualized with literature. Our analysis demonstrates that the thermoelectric properties of electrodeposited films can be accurately evaluated without inflicting any damage to the films.

scholarly journals Electrical properties of pure NiO and NiO:Au thin films prepared by using pulsed laser deposition

2019 ◽  
Vol 14 (29) ◽  
pp. 37-43 ◽  
Author(s):  
Raied K. Jamal
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Electrical Properties ◽  
Transport Mechanism ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Concentration Increase ◽  
Annealing Temperatures ◽  
P Type

The electrical properties of pure NiO and NiO:Au Films which aredeposited on glass substrate with various dopant concentrations(1wt.%, 2wt%, 3wt.% and 4wt.%) at room temperature 450 Coannealing temperature will be presented. The results of the hall effectshowed that all the films were p-type. The Hall mobility decreaseswhile both carrier concentration and conductivity increases with theincreasing of annealing temperatures and doping percentage, Thus,indicating the behavior of semiconductor, and also the D.Cconductivity from which the activation energy decrease with thedoping concentration increase and transport mechanism of the chargecarriers can be estimated.

Electrochemically Deposited Cobalt Thin Films on p‐Type Silicon and Its Characterization

1995 ◽  
Vol 142 (11) ◽  
pp. 3889-3892 ◽  
Author(s):  
C. Wisniewski ◽  
I. Denicoló ◽  
I. A. Hümmelgen
Keyword(s):  
Thin Films ◽  
Type Silicon ◽  
Electrochemically Deposited ◽  
Cobalt Thin Films ◽  
P Type

Enhanced transmittance and mobility of p-type copper iodide thin films prepared at room temperature via a layer-by-layer approach

2019 ◽  
Vol 361 ◽  
pp. 396-402 ◽  
Author(s):  
Fangjuan Geng ◽  
Lei Yang ◽  
Bing Dai ◽  
Shuai Guo ◽  
Gang Gao ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Layer By Layer ◽  
Copper Iodide ◽  
P Type

p-Type Field Effect Transistor and UV-Photoconductive Characteristics of Na Doped ZnMgO Thin Films

2013 ◽  
Vol 668 ◽  
pp. 681-685
Author(s):  
Ya Xue ◽  
Hai Ping He ◽  
Zhi Zhen Ye
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carrier Mobility ◽  
Room Temperature ◽  
Zno Films ◽  
Electrical Measurements ◽  
Acceptor Dopant ◽  
Znmgo Thin Film ◽  
Effect Transistor ◽  
P Type

In this study, the authors have presented results for fabricated ZnO based FET and the UV-photoconductive characteristics of Na doped ZnMgO thin films. The electrical measurements confirmed that the conductivity of the Na doped ZnMgO thin film is p-type, and the carrier mobility was estimated to be 2.3 cm2V-1S-1. Moreover, after exposed to the 365 nm ultraviolet light, the Na doped ZnMgO thin films still exhibited p-type behavior under gate voltage ranging from -5 to 2 V, and the Id increased a little while the carrier mobility did not change much. The photocurrent was measured under a bias of 6 V in air at room temperature. The films performed a higher current intensity after the illumination. The instantaneous rise of the photocurrent was completed when exposed to the 365 nm ultraviolet for 20 s, after switching the ultraviolet off the photocurrent decayed in a slower rate. The enhance rate of photocurrent was about 1.33 %. Conclusively, Na is a considerable acceptor dopant for making high quality p-type ZnO films, and the tiny change in the photocurrent of p-type Na doped ZnMgO thin film made it relatively stable when fabricating LEDs and other optoelectronic devices.

scholarly journals Co-doped p-type ZnO:Al-N Thin Films Grown by RF-Magnetron Sputtering at Room Temperature

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Raul Ramos ◽  
Marcio Peron Franco de Godoy ◽  
Elidiane Cipriano Rangel ◽  
Nilson Cristino da Cruz ◽  
Steven F. Durrant ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Room Temperature ◽  
Rf Magnetron Sputtering ◽  
P Type ◽  
Co Doped

scholarly journals The Role of Dopant Concentration on Conductivity and Mobility of CdTe Thin Films

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ala J. Al-Douri ◽  
F. Y. Al-Shakily ◽  
Abdalla A. Alnajjar ◽  
Maysoon F. A. Alias
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Dopant Concentration ◽  
Glass Substrates ◽  
Order Of Magnitude ◽  
Cdte Thin Films ◽  
P Type ◽  
Substrate Temperatures

Films of CdTe pure and doped with various atomic percentages of Al and Sb (0.5, 1.5 & 2.5) were prepared, and their electrical properties were investigated. The films were prepared by thermal evaporation on glass substrates at two substrate temperatures (Ts=RT& 423 K). The results showed that the conduction phenomena of all the investigated CdTe thin films on glass substrates are caused by two distinct mechanisms. Room temperature DC conductivity increases by a factor of four for undoped CdTe thin films asTsincreases and by 1-2 orders of magnitude with increasing dopant percentage of Al and Sb. In general, films doped with Sb are more efficient than Al-doped films. The activation energy (Ea2) decreases with increasingTsand dopant percentage for both Al and Sb. Undoped CdTe films deposited at RT are p-type convert to n-type with increasingTsand upon doping with Al at more than 0.5%. The carrier concentration decreases asTsincreases while it increases with increasing dopant percentage. Hall mobility decreases more than three times as Al increases whereas it increases about one order of magnitude with increasing Sb percentage in CdTe thin films deposited at 423 K and RT, respectively.

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