60 Result(s)
within
R. Martins
Materials Science
-
Article
Effect of solvents on ZnO nanostructures synthesized by solvothermal method assisted by microwave radiation: a photocatalytic study
The present work reports the synthesis of zinc oxide (ZnO) nanoparticles with hexagonal wurtzite structure considering a solvothermal method assisted by microwave radiation and using different solvents: water (H2
-
Article
Nd-YAG Laser Induced Crystallization on a-Si∶H Thin Films
In this paper we present results concerning the influence of laser energy and shot density on the electrical resistance, X-ray diffraction pattern, and structure obtained by SEM, on recrystallized a-Si:H thin ...
-
Article
The Structure and Composition of Doped Silicon Oxycarbide Microcrystalline Layers Produced by Spatial Separation Techniques
This work presents experimental data concerning the role of the oxygen partial pressure used during the preparation process, on the structure, composition and optoelectronic properties of wide band gap doped m...
-
Article
Role of Power Density, U.V. Light and Hydrogen Dilution on Transition of Amorphous to Microcrystalline Structure on Films Produced by a TCDDC System
The role of deposition condition on content and bond configurations of a–Si:H/μc–Si:H and a–Si:C:H doped films were investigated through IR spectra and correlated with transport properties. The microstructure,...
-
Article
Use of μ-Si:H Wide Band Gap N- and P-Type Materials for Producing Solar Cells by a TCDDC System
Amorphous silicon (a-Si:H) solar cells based on p.i. n junctions have been produced by a Two Consecutive Decomposition and Deposition Chamber (TCDDC) system [1], either using Wide Band Gap-μc (WBG-μc) films or...
-
Article
Polymorphous Silicon Films Produced in Large Area Reactors by PECVD at 27.12 MHz and 13.56 MHz
This work refers to a study performed on polymorphous silicon (pm-Si:H) at excitation frequencies of 13.56 and 27.12 MHz in a large area PECVD reactor. The plasma was characterised by impedance probe measureme...
-
Article
Correlation Between the Tunnelling Oxide and I-V Curves of MIS Photodiodes
In this work we present results of a study performed on MIS diodes with the following structure: substrate (glass) / Cr (2000Å) / a-Si:H n+ (400Å) / a-Si:H i (5500Å) / oxide (0-40Å) / Au (100Å) to determine the i...
-
Article
A next generation TCO Material for display systems: Molybdenum doped Indium oxide thin films
Thin films of indium molybdenum oxide (IMO) were rf sputtered onto glass substrates at room temperature. The films were studied as a function of sputtering power (ranging 40 – 180 W) and sputtering time (rangi...
-
Article
Some studies on Molybdenum doped Indium oxide thin films rf sputtered at room temperature
Thin films of molybdenum doped indium oxide (IMO) were rf sputtered onto glass substrates at room temperature. The films were studied as a function of oxygen volume percentage (OVP) ranging 1.4 - 10.0 in the s...
-
Article
Molybdenum doped Indium Oxide thin films prepared by rf sputtering
Molybdenum doped indium oxide (IMO) thin films rf sputtered at room temperature were studied as a function of oxygen volume percentage (O2 vol. %) varied between 0 and 17.5. The as-deposited films were amorphous ...
-
Article
Optimization of the metal/silicon ratio on nickel assisted crystallization of amorphous silicon
The aim of this work is to optimize the metal/silicon ratio on nickel metal induced crystallization of silicon. For this purpose amorphous silicon layers with 80, 125 and 220 nm thick were used on the top of w...
-
Article
Linearity and sensitivity of MIS position sensitive detectors
The linearity and sensitivity of linear Position Sensitive Detectors (PSD) are the two principal characteristics of sensors to be optimised in sensor fabrication. This work presents several efforts made to und...
-
Article
Metal induced crystallization: Gold versus aluminium
In this work metal induced crystallization was studied using aluminium and gold deposited over 150 nm amorphous silicon films grown by LPCVD. Aluminium and gold layers with thickness between 1 and 5 nm were de...
-
Article
Influence of Hydrogen plasma on electrical and optical properties of transparent conductive oxides
In this work we study the optical and electrical behavior of ZnO:Ga, ITO and IZO films deposited on glass after sustaining different hydrogen plasma conditions and exposure times. This work was complemented by...
-
Article
Amorphous Silicon Based p-i-i-n Structure for Color Sensor
This work deals with the study of the role of the film thickness and composition on the color selectivity of the collecting spectrum of glass/ZnO:Ga/p-a-Si1-xCx:H/ a-Si1-xCx:H /a-Si:H/n-a-Si:H/Al photoelectron...
-
Article
Effect of the Load Resistance in the Linearity and Sensitivity of MIS Position Sensitive Detectors
It is experimentally known that the linearity and sensitivity of the position sensitive detectors (PSD) are dependent on the resistance of the collecting layer and of the load resistance, mainly if the detecti...
-
Article
Enhancement of the Electrical Properties of ITO Deposited on Polymeric Substrates by Using a ZnO Buffer Layer
In this paper we present the effect of the insertion of a non-doped nanocrystalline zinc oxide/buffer layer on the electrical, optical and structural properties of indium tin oxide produced at room temperature...
-
Article
Next Generation of Thin Film Transistors Based on Zinc Oxide
We report high performance ZnO thin film transistor (ZnO-TFT) fabricated by rf magnetron sputtering at room temperature with a bottom gate configuration. The ZnO-TFT operates in the enhancement mode with a thr...
-
Article
Gallium zinc oxide coated polymeric substrates for optoelectronic applications
Highly transparent and conductive ZnO:Ga thin films were produced by rf magnetron sputtering at room temperature on polyethylene naphthalate substrates. The films present a good electrical and optical stabilit...
-
Article
Detection Limits of a nip a-Si:H Linear Array Position Sensitive Detector
This paper presents results of the spatial and frequency detection limits of an integrated array of 32 one-dimensional amorphous silicon thin film position sensitive detectors with a nip structure, under conti...
