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In this study, the low voltage CHEI program is used to achieve single electron injection in nitride layer of nano-scaled SONOS (polysilicon-oxide-nitride-silicon) devices. By investigating various CHEI conditions and different temperature, the best single electron transfer condition is determined. Under this condition, the single electron induced current steps are in good agreement with theoretical result.

Solar-blind metal-semiconductor-metal (MSM) photodetectors (PDs) with Ni/Au semi-transparent interdigitated contact electrodes are fabricated on Al0.4Ga0.6N epi-layer grown by metal-organic chemical vapor deposition on sapphire substrate. The PD exhibits ultra-low dark current in fA range at room temperature (RT) under 20-V bias and a corresponding breakdown voltage higher than 300 V. The PD also shows a maximum RT quantum efficiency of 64% at ~ 275 nm under 10-V bias with a solar-blind/ultraviolet (UV) rejection ratio up to four orders of magnitude. Even at a high temperature of 150°C, the dark current of the PD is still in fA range with a reasonable rejection ratio of more than 8000, suggesting its potential applications for high-temperature deep-UV detection. The ultra-low dark current achieved is believed to be related to the high-temperature AlN buffer layer used in the epi-structure as well as the coplanar configuration of the MSM PD itself.

In 0.3Ga 0.7N metal–insulator–semiconductor (MIS) and metal–semiconductor (MS) surface barrier photodetectors have been fabricated. The In0.3Ga0.7N epilayers were grown on sapphire by metalorganic chemical vapour deposition (MOCVD). The photoresponse and reverse current–voltage characteristics of the In0.3Ga0.7N MIS and MS photodetectors were measured. A best zero bias responsivity of 0.18 A/W at 450 nm is obtained for the In0.3Ga0.7N MIS photodetector with 10 nm Si3N4 insulator layer, which is more than ten times higher than the In0.3Ga0.7N MS pho-todetector. The reason is attributed to the decrease of the interface states and increase of surface barrier height by the inserted insulator. The influence of the thickness of the Si3N4 insulator layer on the photoresponsivity of the MIS photodetector is also discussed.

Thirty-pair Al0.3Ga0.7N/AlN distributed Bragg reflectors centred at 320 nm are designed and grown on sapphire substrates by metalorganic chemical vapour deposition. No cracks are observed in the main area of the 2-inch wafer except for about 4 mm margin under an optical microscope. Regular stack of alternating layers is shown by scanning electron microscopy. Clear two-dimensional growth steps and very low surface roughness are shown by atomic force microscopy (AFM). Well-defined periodicity is shown by high resolution x-ray diffraction. High reflectivity of 93% at 313 nm with a bandwidth of 13 nm is obtained.

The advantages of the p-AlInGaN/GaN superlattices' (SLs) structure as an electron blocking layer (EBL) for InGaN blue light-emitting diodes (LEDs) were studied by experiment and APSYS simulation. Electroluminescence (EL) measurement results show that the LEDs with the p-AlInGaN/GaN SLs' structure EBL exhibited better optical performance compared with the conventional AlGaN EBL due to the enhancement of hole concentration and hole carrier transport efficiency, and the confinement of electrons' overflow between multiple quantum-wells (MQWs) and EBL.