AlGaN-based ultraviolet light-emitting diodes grown on AlN epilayers

Kim, K. H.; Fan, Z. Y.; Khizar, M.; Nakarmi, M. L.; Lin, J. Y.; Jiang, H. X.
November 2004
Applied Physics Letters;11/15/2004, Vol. 85 Issue 20, p4777
Academic Journal
AlGaN-based deep-ultraviolet light-emitting diode (LED) structures, which radiate light at 305 and 290 nm, have been grown on sapphire substrates using an AIN epilayer template. The fabricated devices have a circular geometry to enhance current spreading and light extraction. Circular UV LEDs of different sizes have been characterized. It was found that smaller disk LEDs had higher saturation optical power densities but lower optical powers than the larger devices. This trade-oil between power and power density is a result of a compromise between electrical and thermal resistance, as well as the current crowding effect (which is due to the low electrical conductivity of high aluminum composition n- and p-AlGaN layers). Disk UV LEDs should thus have a moderate size to best utilize both total optical power and power density. For 0.85 mm × 0.85 mm interdigitated LEDs, a saturation optical power of 2.9 mW (1.8 mW) at 305 nm (290 nm) was also obtained under dc operation.


Related Articles

  • 282-nm AlGaN-based deep ultraviolet light-emitting diodes with improved performance on nano-patterned sapphire substrates. Dong, Peng; Yan, Jianchang; Wang, Junxi; Zhang, Yun; Geng, Chong; Wei, Tongbo; Cong, Peipei; Zhang, Yiyun; Zeng, Jianping; Tian, Yingdong; Sun, Lili; Yan, Qingfeng; Li, Jinmin; Fan, Shunfei; Qin, Zhixin // Applied Physics Letters;6/17/2013, Vol. 102 Issue 24, p241113 

    We first report AlGaN-based deep ultraviolet light-emitting diodes (UV-LEDs) grown on nano-patterned sapphire substrates (NPSS) prepared through a nanosphere lithography technique. The AlN coalescence thickness on NPSS is only 3 μm due to AlN's nano-scaled lateral growth, which also leads to...

  • Self-heating effects at high pump currents in deep ultraviolet light-emitting diodes at 324 nm. Chitnis, A.; Sun, J.; Mandavilli, V.; Pachipulusu, R.; Wu, S.; Gaevski, M.; Adivarahan, V.; Zhang, J. P.; Khan, M. Asif; Sarua, A.; Kuball, M. // Applied Physics Letters;10/28/2002, Vol. 81 Issue 18, p3491 

    We present a detailed high-pump-current study of self-heating effects in ultraviolet light-emitting diodes (LEDs) grown on sapphire. For deep ultraviolet LEDs on sapphire, our results establish self-heating to be a primary cause of premature power saturation under dc pumping. Even the flip-chip...

  • Influence of GaN Material Characteristics on Device Performance for Blue and Ultraviolet Light-Emitting Diodes. Merfeld, D. W.; Cao, X. A.; Leboeuf, S. F.; Arthur, S. D.; Kretchmer, J. W.; D'Evelyn, M. P. // Journal of Electronic Materials;Nov2004, Vol. 33 Issue 11, p1401 

    An analysis of blue and near-ultraviolet (UV) light-emitting diodes (LEDs) and material structures explores the dependence of device performance on material properties as measured by various analytical techniques. The method used for reducing dislocations in the epitaxial III-N films that is...

  • Light output improvement of InGaN ultraviolet light-emitting diodes by using wet-etched stripe-patterned sapphire substrates. Pan, Chang-Chi; Hsieh, Chi-Hsun; Lin, Chih-Wei; Chyi, Jen-Inn // Journal of Applied Physics;Oct2007, Vol. 102 Issue 8, p084503 

    GaN-based epilayers are grown on wet-etched stripe-patterned sapphire substrates, with stripes along the <11-20>sapphire and <1-100>sapphire directions, for 400 nm ultraviolet light-emitting diodes (LEDs). The effects of the etching depth and stripe orientation on the structural and optical...

  • Submilliwatt operation of AlGaN-based ultraviolet light-emitting diode using short-period alloy superlattice. Nishida, T.; Saito, H.; Kobayashi, N. // Applied Physics Letters;1/22/2001, Vol. 78 Issue 4, p399 

    Over 0.1 mW ultraviolet output was achieved by an AlGaN-based light-emitting diode. To realize a highly conductive and ultraviolet-transparent layer, a short-period alloy superlattice was introduced. The device was fabricated on SiC substrate. Low electric resistivity due to the short-period...

  • Combinatorial fabrication and studies of intense efficient ultraviolet–violet organic light-emitting device arrays. Zou, L.; Savvate’ev, V.; Booher, J.; Kim, C.-H.; Shinar, J. // Applied Physics Letters;10/1/2001, Vol. 79 Issue 14, p2282 

    Arrays of ultraviolet–violet (indium tin oxide)/[copper phthalocyanine (CuPc)]/[4,4′-bis(9-carbazolyl)biphenyl (CBP)]/[2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4oxadiazole (Bu-PBD)]/CsF/Al organic light-emitting devices, fabricated combinatorially using a sliding shutter...

  • Interfacial electronic structures in an organic light-emitting diode. Lee, S.T.; Wang, Y.M.; Hou, X.Y.; Tang, C.W. // Applied Physics Letters;2/1/1999, Vol. 74 Issue 5, p670 

    Measures the electronic properties for the metal/organic and organic/organic interfaces in an organic light-emitting diode using ultraviolet photoemission spectroscopy. Device configuration; Voltage drop across the metal/organic interface; Applicability of traditional vacuum-level alignment at...

  • Recombination dynamics in ultraviolet light-emitting diodes with Si-doped AlxGa1-xN/AlyGa1-yN multiple quantum well active regions. Chen, K. X.; Xi, Y. A.; Mont, F. W.; Kim, J. K.; Schubert, E. F.; Liu, W.; Li, X.; Smart, J. A. // Journal of Applied Physics;6/1/2007, Vol. 101 Issue 11, p113102 

    Ultraviolet (UV) light-emitting diodes with AlxGa1-xN/AlyGa1-yN multiple quantum well active regions, doped in the barriers with different Si doping levels, show a sharp near-band edge emission line (UV luminescence). Some samples have a broad subband gap emission band centered at about 500 nm...

  • Low-frequency noise of GaN-based ultraviolet light-emitting diodes. Rumyantsev, S. L.; Sawyer, S.; Shur, M. S.; Pala, N.; Bilenko, Yu.; Zhang, J. P.; Hu, X.; Lunev, A.; Deng, J.; Gaska, R. // Journal of Applied Physics;6/15/2005, Vol. 97 Issue 12, p123107 

    Low-frequency fluctuations of current and light intensity were measured for different types of ultraviolet (UV) light-emitting diodes (LEDs) with wavelengths from 280 to 375 nm. These UV LEDs are suitable for studying steady-state and time-varying UV fluorescences of biological materials. The...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics