Tesis doctoral de Alfredo Morales Sanchez
In this thesis, silicon rich oxide [sro, (siox, x<2)] films with different silicon excesses were deposited by low pressure chemical vapor deposition (lpvcd). Besides, si implanted sro (si-sro) films were also fabricated. Si-nps in these films were created after a thermal annealing at high temperature (1100 and 1250° c). The composition, microstructure and optical properties of these sro and si-sro films were analyzed as a function of the different technological parameters, such as silicon excess, si ion implantation dose, and thermal annealing temperature. once the microstructure, composition as well as the optical properties of these materials is known, sro films which exhibited the best photoluminescent (strongest pl) properties were chosen in order to analyze their electrical and electro-optical properties. simple metal-oxide-semiconductor (mos) structures using the sro films as the dielectric layer were fabricated for these studies. Sro films with si-excess of ~4.0 and ~2.2 at.% And thickness ranging from 24 to 80 nm were deposited. The conduction mechanism in these films is analyzed by making use of trap assisted tunnelling (tat) in low electric field as well as fowler-nordheim (fn) tunnelling in high electric fields. the electrical measurements exhibited important results, such as a reduction in capacitance and current during the sweep or after applying a constant bias. These effects are ascribed to the annihilation of conduction paths created by silicon clusters (si-els) inside the sro films. a part from that, some devices exhibited current fluctuations in the form of spike-like peaks and a clear staircase at room temperature. These effects were related to coulomb blockade (cb) effects in the silicon nanoparticles embedded in the sro films. And from the current plateaus, the size of the si-nps (about 1 nm) was calculated. field effect luminescence of these sro films was studied by alternating negative (positive) to positive (negative) voltages (pulsed excitation). Moreover, it is demonstrated that these sro films show el emission in continuous current voltage, observed at naked eye. Multiple shining spots of several colours are seen on the mos-like structure surface when reversely biased. these devices display a broad electroluminescent emission spectrum which goes from 400 nm up to 900 nm. Finally, a correlation between the structural, electrical and luminescent (pl and el) properties is discussed.
Datos académicos de la tesis doctoral «Correlation between optical and electrical properties of materials containing«
- Título de la tesis: Correlation between optical and electrical properties of materials containing
- Autor: Alfredo Morales Sanchez
- Universidad: Autónoma de barcelona
- Fecha de lectura de la tesis: 02/09/2008
Dirección y tribunal
- Director de la tesis
- Carlos Dominguez Horna
- Tribunal
- Presidente del tribunal: Francisco Serra mestres
- nuria Barniol beumala (vocal)
- Juan ignacio Garces gregorio (vocal)
- albert Figueras (vocal)