Study Of Ultraviolet Photoluminescence Enhancement And Device Based On ZnO Micro-cavity

For its direct band gap property,wide bandgap?3.37eV?,higher exciton activation energy?60 meV?,ZnO is an excellent candidate for optoelectronic devices.In recently years,how to improve the optical performance of ZnO micro-cavities and how to fabricate ZnO based light emission devices with higher optical performance were good research tops.Surface plasma is electrons oscilation under light excitation.It can strongly localize and enhance the electromagnetic fields around the metal/dielectric interface thus improve the light emission of ZnO.Structural optimum is a key issue to improve the optical performance devices with higher injection efficiency and reduced interfacial loss.In this paper,we fabricate ZnO microrods,study the lasing and surface plasma enhanced lasing performance in ZnO micro-cavity.Including the lasing enhancement,mode modulation and electrically pumped lasing properties are well studied through experimental and simulation.The main studies issues are as follow:1.High quality ZnO micro-cavities were fabricated and surface plasmon was introduced to improve the lasing performance of ZnO.Through the analyzing of PL and TRPL spectra,we studied the PL enhancement and carrier combination process in Au/ZnO and grapheme/ZnO hybrid structures.While introducing another excitation lasing of 532 nm,SPs coupling induced electrons transporting mechanism was studied.While designing different interface through O₂ plasmon treatment in grapheme/ZnO hybrid structure,the energy coupling mechanism in graphene covered ZnO was demonstrated with synchronously measurement of PLand TRPL.2.After fully understand the SPs coupling mechanism,different structure was designed to study the lasing modulation of ZnO under loss and gain competition.Through introducing extra gain with Al surface plasmon,we studied the cavity gain related mode evaluation in hydrothermal ZnO F-P cavities.Through introducing extra gain with Al surface plasmon and extra loss with GaN,we studied the interfacial loss induced intensity modulation in ZnO WGM cavities.3.We built LED with ZnO and GaN,studied the interfacial modulation of difference devices.Through introducing MgO and AlN as electron barrier layer,we realized ultraviolet emission of the device.Through introducing graphene layer into the device,we studied the brightness improvement and wavelength blueshift of the devices.4.We fabricated laser diode based on individual ZnO micro cavity and GaN.Study the electroluminescence of different structures under higher current density via home-made photoelectric detection system.Though improving the electrical conductivity by doping,increasing the cavity size and introducing AlN electron barrier layer,we realized the mode oscillation and lasing in optimized device.