Ultraviolet semiconductor lasers are widely used for applications in photonics, information storage, biology and medical therapeutics. Although the performance of gallium nitride ultraviolet lasers has improved significantly over the past decade, demand for lower costs, higher powers and shorter wavelengths has motivated interest in zinc oxide (ZnO), which has a wide direct bandgap and a large exciton binding energy. ZnO-based random lasing has been demonstrated with both optical and electrical pumping, but random lasers suffer from reduced output powers, unstable emission spectra and beam divergence. Here, we demonstrate electrically pumped Fabry-Perot type waveguide lasing from laser diodes that consist of Sb-doped p-type ZnO nanowires and n-type ZnO thin films. The diodes exhibit highly stable lasing at room temperature, and can be modelled with finite-difference time-domain methods.

We report on p-n junction light-emitting diodes fabricated from MgZnO / ZnO / AlGaN / GaN triple heterostructures. Energy band diagrams of the light-emitting diode structure incorporating piezoelectric and spontaneous polarization fields were simulated, revealing a strong hole confinement near the n-ZnO / p-AlGaN interface with a hole sheet density as large as 1.82 ϫ 10 13 cm −2 for strained structures. The measured current-voltage ͑IV͒ characteristics of the triple heterostructure p-n junctions have rectifying characteristics with a turn-on voltage of ϳ3.2 V. Electron-beam-induced current measurements confirmed the presence of a p-n junction located at the n-ZnO / p-AlGaN interface. Strong optical emission was observed at ϳ390 nm as expected for excitonic optical transitions in these structures. Experimental spectral dependence of the photocurrent confirmed the excitonic origin of the optical transition at 390 nm. Light emission was measured up to 650 K, providing additional confirmation of the excitonic nature of the optical transitions in the devices.

Morphological evolution of InGaN/GaN quantum-well heterostructures grown by metalorganic chemical vapor deposition

The cooling effect on structural, electrical, and optical properties of epitaxial a-plane ZnO:Al on r-plane sapphire grown by pulsed laser deposition Appl. Phys. Lett. 101, 151907 (2012) Multiphonon scattering and photoluminescence of two dimensional ZnS nanosheets grown within Na-4 mica J. Appl. Phys. 112, 074321 (2012) Growth study of nonpolar Zn1−xMgxO epitaxial films on a-plane bulk ZnO by plasma-assisted molecular beam epitaxy Appl. Phys. Lett. 101, 122106 (2012) Mechanical and electrical characterization of semiconducting ZnO nanorings by direct nano-manipulation Appl. Phys. Lett. 101, 081910 (2012) Observation of magnetism, low resistivity, and magnetoresistance in the near-surface region of Gd implanted ZnO Appl.

ZnO nanorods and nanowires are promising candidates as new types of high‐sensitivity ultraviolet (UV) photodetectors due to their wide bandgap and large aspect ratio. In this study, single‐crystalline ZnO nanorods were grown on glass substrates by a hydrothermal method. Specific structural, morphological, electrical, and optical measurements were carried out. A single ZnO nanorod‐based photodetector was fabricated using the in‐situ lift‐out technique in a focused ion beam (FIB/SEM) instrument and characterized. With a source wavelength of 370 nm and an applied bias of 1 V, the responsivity of the ZnO nanorod is 30 mA/W. The single ZnO nanorod photodetector exhibits an ultraviolet (UV) photoresponse promising for potential applications as cost‐effective UV detectors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)