@article{zhang_dhawan_wellenius_suresh_muth_2007, title={Planar ZnO ultraviolet modulator}, volume={91}, ISSN={["0003-6951"]}, DOI={10.1063/1.2770995}, abstractNote={A planar electroabsorption modulator suitable for spatial light modulation has been constructed. The device operates near the band edge of zinc oxide at 3.3eV and is based on broadening and shifting of the unconfined exciton with an externally applied electric field. The ZnO active layer was deposited on an aluminum/titanium oxide dielectric on an indium tin oxide conducting layer on glass. A transparent conductive InGaZnO layer on a spin on glass insulator served as the top contact, allowing high electric fields to be applied transverse to the ZnO layer. The modulator operates at room temperature in transmission mode with +45% modulation at 373nm and −18% modulation at 380nm at 140V applied bias, corresponding to ∼450kV∕cm electric field across the ZnO active layer.}, number={7}, journal={APPLIED PHYSICS LETTERS}, author={Zhang, X. Y. and Dhawan, A. and Wellenius, P. and Suresh, A. and Muth, J. F.}, year={2007}, month={Aug} }
 @article{park_reitmeier_fothergill_zhang_muth_davis_2006, title={Growth and fabrication of AlGaN-based ultraviolet light emitting diodes on 6H-SiC(0001) substrates and the effect of carrier-blocking layers on their emission characteristics}, volume={127}, ISSN={["0921-5107"]}, DOI={10.1016/j.mseb.2005.10.019}, abstractNote={Abstract Growth, fabrication, and the electrical and optical characterization of ultraviolet light emitting diodes and their components, including AlxGa1−xN films, quantum wells (QWs), and ohmic contacts, and the problems encountered in the process integration of these components have been investigated. Ni/Au ohmic contacts with specific contact resistivities of 2.2 × 10−4 and 2.0 × 10−2 Ω cm2 were achieved on annealed, Mg-doped ([Mg] ∼ 5 × 1019 cm−3), p-type GaN layers that had been cleaned in HCl at 85 °C and on the backside of the SiC substrates after annealing in nitrogen, respectively. The emission intensity of the diodes increased with an increase in the number of Al0.06Ga0.94N/Al0.10Ga0.90N QWs and with the use of Si-doped n-type barrier layers. The highest intensities of the principle emission at 353 nm were measured at all values of the injection current in the device with a p-type carrier-blocking layer at the top of the QWs; this device also exhibited the highest values of light output power. Growth of an n-type carrier-blocking layer at the bottom of the QWs had an adverse effect on their characteristics. A broad peak centered at ∼540 nm exhibited yellow luminescence and was present in the spectra acquired from all the devices. This peak is attributed to absorption of the ultraviolet emission by and re-emission from the p-GaN and/or to the luminescence from the AlGaN within QWs by current injection.}, number={2-3}, journal={MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY}, author={Park, JS and Reitmeier, ZJ and Fothergill, D and Zhang, XY and Muth, JF and Davis, RF}, year={2006}, month={Feb}, pages={169–179} }
 @article{park_fothergill_zhang_reitmeier_muth_davis_2005, title={Effect of carrier blocking layers on the emission characteristics of AlGaN-based ultraviolet light emitting diodes}, volume={44}, ISSN={["0021-4922"]}, DOI={10.1143/jjap.44.7254}, abstractNote={ 
  AlGaN-based thin film heterostructures suitable for ultraviolet light emitting diodes have been grown and fabricated into working devices with and without p-type and n-type AlGaN carrier-blocking layers at the top and the bottom of the quantum wells, respectively. The principal emission from each device occurred at 353 nm. The highest intensities of this peak were measured at all values of the injection current in the device with a p-type carrier-blocking layer at the top of the quantum well; this device also exhibited the highest values of light output power. Growth of an n-type carrier-blocking layer at the bottom of the quantum wells had an adverse effect on the light emitting diode characteristics. A broad peak centered at ∼540 nm exhibited yellow luminescence and was present in the spectra acquired from all the devices. This peak is attributed to absorption of the UV emission by and re-emission from the p-GaN and/or to the luminescence from the AlGaN within quantum wells by current injection. The intensity of this peak increased and saturated by the same order of magnitude as the intensity of the UV emission at 353 nm. 
  }, number={10}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS}, author={Park, JS and Fothergill, DW and Zhang, XY and Reitmeier, ZJ and Muth, JF and Davis, RF}, year={2005}, month={Oct}, pages={7254–7259} }
 @article{muth_zhang_cai_fothergill_roberts_rajagopal_cook_piner_linthicum_2005, title={Gallium nitride surface quantum wells}, volume={87}, number={19}, journal={Applied Physics Letters}, author={Muth, J. F. and Zhang, X. and Cai, A. and Fothergill, D. and Roberts, J. C. and Rajagopal, P. and Cook, J. W. and Piner, E. L. and Linthicum, K. J.}, year={2005} }