TY - JOUR TI - Gallium nitride surface quantum wells AU - Muth, J. F. AU - Zhang, X. AU - Cai, A. AU - Fothergill, D. AU - Roberts, J. C. AU - Rajagopal, P. AU - Cook, J. W. AU - Piner, E. L. AU - Linthicum, K. J. T2 - Applied Physics Letters DA - 2005/// PY - 2005/// VL - 87 IS - 19 ER - TY - JOUR TI - Effect of carrier blocking layers on the emission characteristics of AlGaN-based ultraviolet light emitting diodes AU - Park, JS AU - Fothergill, DW AU - Zhang, XY AU - Reitmeier, ZJ AU - Muth, JF AU - Davis, RF T2 - JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS AB - 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. DA - 2005/10// PY - 2005/10// DO - 10.1143/jjap.44.7254 VL - 44 IS - 10 SP - 7254-7259 SN - 0021-4922 KW - light emitting diode KW - ultraviolet KW - AlGaN KW - carrier blocking layer KW - quantum well ER -