Publications

Export 4 results:
Sort by: Author [ Title  (Asc)] Type Year
A B C D E F G H I J K L M N O P Q R [S] T U V W X Y Z   [Show ALL]
S
Contreras, J., J. Tornero, I. Ferreira, R. Martins, L. Gomes, and E. Fortunato, "Simulated and Real Sheet-of-Light 3D Object Scanning Using a-Si:H Thin Film PSD Arrays", Sensors, vol. 15, issue 12, pp. 29938-29949, 2015. Abstract

A MATLAB/SIMULINK software simulation model (structure and component blocks) has been constructed in order to view and analyze the potential of the PSD (Position Sensitive Detector) array concept technology before it is further expanded or developed. This simulation allows changing most of its parameters, such as the number of elements in the PSD array, the direction of vision, the viewing/scanning angle, the object rotation, translation, sample/scan/simulation time, etc. In addition, results show for the first time the possibility of scanning an object in 3D when using an a-Si:H thin film 128 PSD array sensor and hardware/software system. Moreover, this sensor technology is able to perform these scans and render 3D objects at high speeds and high resolutions when using a sheet-of-light laser within a triangulation platform. As shown by the simulation, a substantial enhancement in 3D object profile image quality and realism can be achieved by increasing the number of elements of the PSD array sensor as well as by achieving an optimal position response from the sensor since clearly the definition of the 3D object profile depends on the correct and accurate position response of each detector as well as on the size of the PSD array.

Ferreira, M., J. Loureiro, A. Nogueira, A. Rodrigues, R. Martins, and I. Ferreira, "SnO2 thin Film Oxides Produced by rf Sputtering for Transparent Thermoelectric Devices", Mater. Today-Proc, vol. 2, issue 2, pp. 647-653, 2015. AbstractDOI

The combination of high transparency and good thermoelectric properties of SnO2 can open new field of applications for the thin film thermoelectric materials. Here we report on SnO2 thin films with transmittance above 90%, resistivity bellow 10-3 Ωm and a Power Factor around 10-4 W/m.K2, for a Seebeck of -255 μV/K, at room temperature. The effect of film thickness and post-deposition annealing on the thermoelectric properties were analysed. The performances of a single layer thermoelectric device are also presented.

Marques, A. C., J. Faria, P. Perdigão, B. M. M. Faustino, R. Ritasalo, K. Costabello, R. C. da Silva, and I. Ferreira, "Stability under humidity, UV-light and bending of AZO films deposited by ALD on Kapton", Scientific Reports, vol. 9, pp. 17919, 2019.
Sousa, D. M., J. C. Lima, and I. Ferreira, "Synthesis of Cadmium Selenide Quantum Dots, Using 2, 2‐Bipyridine as a Capping and Phase Transfer Agent", ChemistrySelect, vol. 2, issue 3, pp. 1271-1274, 2017. AbstractDOI

Cadmium selenide quantum dots (CdSe QDs), were synthesized by one‐pot or water‐to‐organic phase transfer and capped with molten 2,2′‐bipyridine (bipy). The obtained CdSe QDs by the two‐step procedure, reveal average sizes of 2 nm while the one‐pot are mixed with secondary salt products and bipy and are undetectable by TEM. However the absorption peak of both CdSe QDs was at 425 nm and the emission band is centered at 535 nm, with a band width at half height of 77 nm, when excited with 425 nm light. The two‐step CdSe QDs synthesis has the great advantage of capping the CdSe QDs with bipy, forming a solid phase, which is easily stored and dispersed in most of the organic solvents. On the other hand, the one‐pot procedure requires an extra step to remove the secondary products.