High-efficiency Si-based Near-infrared Luminescent Devices For The Optical Interconnection Application

With the rapid development of integrated circuit industry,the level of semiconductor process has been close to its physical limits.The combination of photonic devices and microelectronic technology to achieve optical interconnection is one of the key strategies that today scientists at home and abroad try to explore.The most challenging things are to overcome the indirect band gap of Si and to find an efficient and stable Si-based light source.In recent years,it has been a hot topic in academic world that doping suitable impurities into the Si-based film as illuminating centers and then obtaining a photoelectron illuminating device satisfying optical interconnection.In order to solve low luminescence efficiency of all-Si-based materials,quantum dots with high number density and size tunable are doped as sensitizers in this thesis,and the near-infrared luminescence of Si-based film from transition metal ions and rare earth ions has been enhanced by an efficient energy transfer process.The sol-gel wet chemistry strategy based on spin coating technique is used to prepare amorphous Si O2 films with SnO₂ quantum dots and rare earth Er3+ ions,or with Au quantum dots and transition metal Bi ions,and then the films are characterized by various techniques.The near-infrared luminescence is enhanced under the conditions of optical pumping and electric injection,and the illuminating mechanism and energy transfer mechanism are deeply analyzed.To sum up,the main content of manuscript is listed as follows:The conformation of SnO₂ and Au quantum dots are completed by a sol-gel wet chemistry strategy based on spin coating technique.With optimizing process conditions and characterizing microstructure by various instruments,quantum dots with average size of 2.1 to 5.2 nm and high number density embedded in Si-based films are successfully fabricated.The results of relevant optical test analysis provide a prerequisite for these quantum dots sensitized the luminescence of transition metal ions and rare earth ions.Near-infrared?NIR?luminescence origin of Bi-doped amorphous silica thin film is elucidated by the XPS characterizations and selective photoluminescence?PL?measurements.The excitation wavelength dependent NIR luminescence suggests the co-existence of two different types of Bi-related active centers,Bi0 and Bi+,should contribute to the NIR PL emissions at 1150 nm and 1280 nm,respectively.Via controls of the doping amounts of Au ions,the NIR PL emission of Bi ions in amorphous silica thin film can be wavelength-tunable and enhanced by nearly 300% on the optimum Au ions doping amount.Temperature-dependent PL emission spectra demonstrate parts of Au ions play a role of eliminating hydroxyl groups and give rise to greatly enhanced NIR PL emission intensity.SnO₂ quantum dots with average size of 5.2 nm are selected as sensitizers,and thus the NIR luminescence of rare earth Er3+ ions at 1550 nm is enhanced by three orders of magnitude.There are several sharp sensitizer-related excitation peaks in PL emission spectrum,which confirms the resonance energy transfer between SnO₂ quantum dots and rare earth Er3+ ions.The luminescence lifetime of each part in system is analyzed by transient photoluminescence spectroscopy,and the resonance energy transfer efficiency between SnO₂ quantum dots and rare earth Er3+ ions is calculated to be as high as 63.4%.The related electroluminescence prototype device is designed and the J-V test indicates a carrier transport composite SCLC model.After incorporation of SnO₂ quantum dots with average size of 5.2 nm,there exist the NIR electroluminescence efficiency enhanced by 16 times,the greatly reduced turn-on voltage and the stable operation with a long time,which provides a possible technology for NIR high-efficiency light sources in Si-based optoelectronic integration.