Martins, R., Ferreira Fortunato I. E. "
Growth model of gas species produced by the hot-wire and hot-wire plasma-assisted techniques."
Key Engineering Materials. 230-232 (2002): 603-606.
AbstractThe model presented is based on the heat transfer and energy balance equations that rule the set of physical and chemical interactions that take place on the gas phase of a growth process, assuming that the deposition process occurs under laminar dynamic flow conditions (Knudsen number below 1). In these conditions, the chemistry and physics of the process involved in the growth mechanism of silicon thin films produced by the hot wire or the hot-wire plasma assisted technique can be proper derived by balance equations that supply information about how the plasma density, the gas dilution and the gas temperature influence the growth mechanism and the equilibrium of the concentration of species presented on the growth surface. The model developed establishes a relation between the abundance species formed and the parameters initiators of the process such as the filament temperature and the rf power density used.
Martins, R., Fantoni Vieira A. M. "
Tailoring defects on amorphous silicon pin devices."
Journal of Non-Crystalline Solids. 164-166 (1993): 671-674.
AbstractThis paper deals with a new model and structure able to tailor defects in pin devices. The model assumes the usual density of states profile, including donor and acceptor like states inside the mobility gap and has the capability to simulate the transient and steady state device behavior. The new structure is based in two interfacial defectous layers, located at the junctions, acting as "gettering" centers to tailor the defects. The role of the interlayer and its thickness on device performances will be also discussed. © 1993.
Martins, R., Ferreira Fernandes Fortunato I. F. E. "
Role of the deposition conditions on the properties presented by nanocrystallite silicon films produced by hot wire."
Journal of Non-Crystalline Solids. 227-230 (1998): 901-905.
AbstractThe aim of this work is to study the role of hydrogen dilution and filament temperature on the properties of nanocrystalline silicon thin films (undoped and doped) produced by the hot wire technique. These deposition parameters are correlated to the film's structure, composition and electro-optical properties with special emphasis on boron doped nanocrystalline silicon carbide reported here. © 1998 Elsevier Science B.V. All rights reserved.
Martins, Rodrigo, Fortunato Elvira. "
Simulation of the lateral photo effect in large-area 1D a-Si:H p-i-n thin-film position-sensitive detectors."
Proceedings of SPIE - The International Society for Optical Engineering. Vol. 2397. 1995. 745-756.
AbstractThe aim of this work is to provide the basis for the interpretation, under steady state, of the lateral photoeffect in p-i-n a-Si:H 1D Thin Film Position Sensitive Detectors (1D TFPSD) through an analytical model. The experimental data recorded in 1D TFPSD devices with different performances are compared with the predicted curves and the obtained correlation's discussed.
c c Martins, N.a, Canhola Quintela Ferreira Raniero Fortunato Martins P. a M. b. "
Performances of an in-line PECVD system used to produce amorphous and nanocrystalline silicon solar cells."
Thin Solid Films. 511-512 (2006): 238-242.
AbstractThis paper presents the performances of an in-line plasma enhanced chemical vapor deposition system constituted by 5 chambers and one external unloaded chamber used in the simultaneous manufacturing of 4 large (30 cm × 40 cm) solar cells deposited on glass substrates. The system is fully automatically controlled by a Programmable Logic Controller using a specific developed software that allows devices mass production without losing the flexibility to perform process innovations according to the industrial requests, i.e. fast and secure changes and optimizations. Overall, the process shift is of about 15 min per each set of 4 solar cells. Without a buffer layer, solar cells with efficiencies of about 9% were produced by the proper tuning of the i-layer production conditions. © 2005 Elsevier B.V. All rights reserved.