Amplified Spontaneous Emission From ZnO in n-ZnO/p-GaN Heterojunction Light-Emitting Diodes With an External-Feedback Reflector

Ultraviolet Electroluminescence of Light-Emitting Diodes Based on Single n-ZnO/p-AlGaN Heterojunction Nanowires

“…One dimensional (1D) semiconductor nanowires (NWs) based on ZnO have been successfully assembled into various kinds of short-wave optoelectronic (OE) devices for wide potential applications and green synthetic processing over years because they exhibit strong excitonic effects due to their direct wide band gap of 3.3 eV at room temperature and their large exciton binding energy of 60 meV. − However, the difficulties inherent in the fabrication of high quality p-type ZnO nanowires have hindered their application in light-emitting devices (LEDs) and photovoltaic (PV) devices based on ZnO homojunctions. − As an alternative approach, ZnO/GaN heterojunction devices, particularly in LEDs, have been achieved and are continuously being improved with elaborate designs by virtue of the similarity in physical properties especially the small lattice mismatch (1.8%) between ZnO and GaN. − Interestingly, with the development of nanotechnology more and more research groups pay much attention to fabricating OE devices based on a single nanowire (SNW) in recent years because SNW OE device is more favorable than others attributed to the requirement for the integration down to nanoscale and better controllability over parameters compared to the average information of nonuniform samples. ,, Additionally, these nanowire-based functional elements, such as nanolasers, , photodetectors, field effect transistors, , and a host of other devices, have attracted a great deal of attention and have been demonstrated. Nevertheless, the study of nanodevices of LEDs based on single heterostuctured NW has rarely been reported, although there have been many efforts directed toward the heterojunction synthesis containing SNW and thin film. ,, …”

ZnO-based ultra-violet light emitting diodes and nanostructures fabricated by atomic layer deposition

“…Figure 3(a) shows RT EL spectra of the n-ZnO/ p-GaN:Mg LED. The multiple Gaussian functions were used to fit the EL spectra to extract the spectral peaks associated with the light emission from GaN and ZnO, as shown in [17]. A comparison between EL and PL spectra reveals that the spectral peak around 425 nm is attributed to the light emission from the Mg acceptor levels in p-GaN, and the EL at 391 nm originates from the n-ZnO layer.…”

“…Over the last few years, we have investigated ZnObased UV LEDs and nanostructures fabricated by ALD, demonstrating that ALD is one of the noteworthy techniques to prepare high-quality ZnO required for these devices. Here, we review our electro-optical and structural investigations on ZnO films and nanostructures [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], which were performed using x-ray diffraction (XRD) and various electron microscopy techniques as well as spectroscopy analyses.…”

Bifunctional Photovoltaic and Violet Electroluminescent Devices Based on $n\hbox{-}{\rm ZnO}/n\hbox{-}{\rm GaN}$ Heterojunctions

“…It can be expected that the depletion region of the n-n heterojunction is mostly resided in the n-GaN region, and the radiative recombination occurs mainly in the n-GaN region. Therefore, the violet emission peak is related with the shallow donor levels of n-GaN, while the weak UV peak results from the near-band edge emission of n-ZnO [11]. The inset of Fig.…”