A5028460203- ZnO doping and properties
- Diamond and Carbon-based Materials Research
- Thin-Film Transistor Technologies
- Metal and Thin Film Mechanics
- Copper-based nanomaterials and applications
- Gas Sensing Nanomaterials and Sensors
- Nanowire Synthesis and Applications
- Semiconductor materials and devices
- High-pressure geophysics and materials
- Ga2O3 and related materials
- Electronic and Structural Properties of Oxides
- Thermal Radiation and Cooling Technologies
- Silicon Nanostructures and Photoluminescence
- Analytical chemistry methods development
- Transition Metal Oxide Nanomaterials
- Thermal properties of materials
- Pigment Synthesis and Properties
- Electrochemical Analysis and Applications
- Laser-induced spectroscopy and plasma
- Fullerene Chemistry and Applications
- Advanced Thermoelectric Materials and Devices
- Analytical Chemistry and Sensors
- Carbon Nanotubes in Composites
- GaN-based semiconductor devices and materials
- Catalytic Processes in Materials Science
Universidade Nova de Lisboa
2010-2019
Hovione (Portugal)
2019
Faculdade de Tecnologia e Ciências
2014
Nova Institut
2013
Uninova
2011-2012
Universidade de São Paulo
2005
National Institute for Space Research
1997
Instituto Tecnológico de Aeronáutica
1996-1997
P-type thin-film transistors (TFTs) using room temperature sputtered SnOx (x<2) as a transparent oxide semiconductor have been produced. The films show p-type conduction presenting polycrystalline structure composed with mixture of tetragonal β-Sn and α-SnOx phases, after annealing at 200 °C. These exhibit hole carrier concentration in the range ≈1016–1018 cm−3; electrical resistivity between 101–102 Ω cm; Hall mobility around 4.8 cm2/V s; optical band gap 2.8 eV; average...
A complementary metal oxide semiconductor (CMOS) device is described. The based on n-(In-Ga-Zn-O) and p-type (SnOx) active semiconductors uses a transparent conductive (In-Zn-O) as gate electrode that sits flexible, recyclable paper substrate simultaneously the dielectric.
Copper oxide (Cu2O) thin films were used to produce bottom gate p-type transparent thin-film transistors (TFTs). Cu2O was deposited by reactive rf magnetron sputtering at room temperature and the exhibit a polycrystalline structure with strongest orientation along (111) plane. The TFTs improved electrical performance such as field-effect mobility of 3.9 cm2/V s an on/off ratio 2×102.
Abstract The ability to process and dimensionally scale field‐effect transistors with on paper integrate them as a core component for low‐power‐consumption analog digital circuits is demonstrated. Low‐temperature‐processed p‐ n‐channel integrated oxide thin‐film in the complementary metal semiconductor (CMOS) inverter architecture are seamlessly layered mechanically flexible, low‐cost, recyclable substrates. possibility of building these using low‐temperature processes opens door new...
This work reports enhanced thermoelectric properties of transparent thin films. The influence the composition, thickness and deposition method has been studied, reaching a <italic>ZT</italic> > 0.1 at room temperature.
This work reports on the role of structure and composition determination performances p-type SnOx TFTs with a bottom gate configuration deposited by rf magnetron sputtering at room temperature, followed post-annealed step up to 200 °C different oxygen partial pressures (Opp) between 0% 20% but where conduction was only observed in narrow window, from 2.8% 3.8%. The were evaluated XRD Mössbauer spectroscopic studies that allows identify best phases/compositions thicknesses (around 12 nm) be...
Thin-films of copper oxide <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$({\hbox{Cu}}_{x}{\hbox{O}})$</tex></formula> were produced by thermal oxidation metallic (Cu) at different temperatures (150–450 xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\ ^{\circ}{\hbox{C}}$</tex></formula> ). The films 200, 250 and 300 showed high Hall motilities 2.2, 1.9 1.6...
In this work, the nonisothermal sintering behavior of as‐received commercial high purity ZnO micrometric (m_ ), submicrometric (sm_ ) and nanometric (n_ powders was studied. The for sputtering target production evaluated by changing green density samples from 62% theoretical ( TD to 35%. We observed that n_ powder, maximum shrinkage rate (MSR) temperature T MSR not affected density, it reached at lower temperatures (~710°C) compared with m_ sm_ powders. For these powders, increased 803°C...
Thin-films of copper oxide (Cu <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> O) were sputtered from a metallic (Cu) target and studied as function oxygen partial pressure (O <sub xmlns:xlink="http://www.w3.org/1999/xlink">PP</sub> ). A Cu film with cubic structure obtained 0% O has been transformed to xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> phase for the increase in 9% but then changed monoclinic CuO (for ≥ 25%). The variation...
P-type thin-film transistors (TFTs) using room temperature sputtered tin and copper oxide as a transparent semiconductor have been produced on rigid paper substrates. The SnO<sub>x</sub> films shows p-type conduction presenting polycrystalline structure composed with mixture of tetragonal β-Sn α-SnO<sub>x</sub> phases, after annealing at 200 °C. These exhibit hole carrier concentration in the range ≈ 10<sup>16</sup>-10<sup>18</sup> cm<sup>-3</sup>, electrical resistivity...
We report the effect of a disperse carbon interlayer between n-a-Si:H layer and an aluminium zinc oxide (AZO) back contact on performance amorphous silicon solar cells. Carbon was incorporated to AZO film as revealed by x-ray photoelectron spectroscopy energy-dispersive analysis. Solar cells fabricated glass substrates using in performed better when present their structure. They exhibited initial efficiency 11%, open-circuit voltage Voc = 1.6 V, short-circuit current JSC 11 mA cm−2 filling...
This work reports the role of structure and composition on determination performances p-type SnOx TFTs deposited by rf magnetron sputtering at room temperature, followed a post-annealed step up to 200 &deg;C different oxygen partial pressures (Opp), between 0% 20%, but where conduction was only observed 2.8&ndash;3.8%. The were evaluated XRD M&ouml;ssbauer spectroscopic studies. study allows identify best phases/compositions thicknesses (around 12 nm) be used that lead production...
The main requirements for transparent conducting oxide (TCO) films acting as electrodes are a high transmission rate in the visible spectral region and low resistivity.However, many cases, tolerance to temperature humidity exposure is also an important requirement be fulfilled by TCOs assure proper operation durability.Besides improving current encapsulation methods, corrosion resistance of developed must enhanced warrant performance optoelectronic devices.In this paper aluminum-doped zinc...
In obtaining uniform array of ZnO 1D nanostructures, especially using solution based methods, the thickness and morphology epitaxial seeds layer are very important. The paper presents effect Al:ZnO on properties nanowires grown by hydrothermal method. Compact vertically aligned nanostructures were obtained. Concentration 0.02 M zinc nitrate was found to be optimal for growing with diameters up 50 nm lengths between 1.5 2.5 microns. Using 0.04 solution, nanorods diameter 100 correlation...