Research On Silicon-Based Efficient Luminesence And Devices

Nano-silicon structure has many optoelectronic characteristics differ from bulk silicon due to its quantum confinement effect. It show extensive application prospect in light-emitting device, light-detector, optoelectronic integrated device, and sensor. This dissertation focuses on luminescence of two nano-silicon materials which active in silicon-based luminescence research since 1990: Er3+-doped silicon and Porous Silicon(PSi). As for luminescence from Er-doped silicon, We discuss its luminescence mechanism and energy transfer mechanism theoretically, and point out three non-radiation process affecting effective luminescence: Auger process, back-transfer process of energy, up-conversion effect. Also analyze the influence of thickness of SiO2,anneal temperature,concentration and film structure on luminescence. At present, some difference still exists in the luminescence mechanism and formation mechanism of porous silicon. Different preparation conditions can seriously affect its PL properties. That's the reason why many research results diverge mostly. By comparing and analyzing the influence of oxidizing current density, oxidizing duration, concentration, and naturally oxidizing duration on PL spectra, we confirm that luminescence peak of PSi will have a blue-shift with increasing current density to some extent. Desired stronger luminescence need appropriate selection of current density. With erosion time extending, luminescence peak will also have a blue-shift. When concentration of HF solution is low enough, peak site move to direction of low energy as concentration increasing, if concentration is high, then it will direct to high energy end. As to natural oxidizing of PSi in the air, its luminescence peak still have a blue-shift, while intensity will decrease with lay time extending. Finally, experimental results are explained by quantum confinement model and luminescence center model. Besides this, microcavity is introduced into porous silicon luminescence. We simulate its characteristics by professional software. In succession to the discussion above, a developed optoelectronic unit can be applied to optical interconnect is presented. It includes a porous Si light-emitting diode (LED) connected with a photo detector by an alumina waveguide. Main attention has been devoted to the enhancement of LED parameters. Quantum efficiency as high as 0.4% has been reached. The delay time of 1.2 ns and the rise time of 1.5 ns have been measured for the diodes. Further improvements are also discussed.