25 SEPIEMBHI 1995
`
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`Vizio EX1007 Page 0001
`
`Vizio EX1007 Page 0001
`
`

`

`APPLIED PHYSICS LETTERS
`
`Vol. 67, No. 13, 25 September 1995
`
`CODEN: APPLAB
`
`ISSN: 0003-6951
`
`OPTICS
`1797 Chirp of passively and actively mode-locked semiconductor lasers
`
`1800 Grating coupled multicolor quantum well infrared photodetectors
`
`1803 Pulsed laser deposition of BaTI03 thin films and their optical
`properties
`1806 Optical heterodyne detection of 60 GHz electro-optic modulation
`from polymer waveguide modulators
`
`1809 Picosecond spectroscopy of optically modulated high-speed laser
`diodes
`
`1812 Double layers of single domains formed by rapid thermal annealing
`of proton-exchanged LiTa03
`1815 Laser diode pumped 106 mW blue upconverslon fiber laser
`
`1818 New nonlinear optical crystal: Cesium lithium borate
`
`1821 Wavelength insensitive passive polarization converter fabricated by
`poled polymer waveguides
`1824 Physical modeling of pyrometric interferometry during molecular
`beam epitaxial growth of 111-V layered structures
`
`FLUIDS, PLASMAS, AND ELECTRICAL DISCHARGES
`1827 Generalized formula for the surface stiffness of fluid-saturated
`porous media containing parallel pore channels
`
`CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES
`
`1830 Characterization of structural defects in wurtzite GaN grown on 6H
`SiC using plasma-enhanced molecular beam epitaxy
`
`1833 Stress evolution during the growth of ultrathin layers of iron and
`iron silicide on Si(111)
`1836 Epitaxial electro-optical Sr xBa1 _ xNb20 6 films by single-source
`plasma-enhanced metalorganic chemical vapor deposition
`
`1839 Effects of hydrogen addition and growth-etch cycling on the
`oxy-acetylene torch deposition of homoepitaxlal diamond
`1841 Elect ron spin resonance observations of exclmer-laser-lnduced
`paramagnetic centers in tellurite glasses
`1844 Surface acoustic wave reflections from a proton exchanged d ispersive
`dot array
`1847 Evidence of interstitial location of Er atoms Implanted into silicon
`
`(Continued)
`
`M. Schell, J. Yu, M. Tsuchiya,
`T. Kamiya
`M. Z. Tidrow, K. K. Choi, A. J. DeAnni,
`W. H. Chang, S. P. Svensson
`D. H. Kim, H. S . Kwok
`
`Wenshen Wang, Datong Chen,
`Harold R. Fetterman, Yongqiang Shi,
`William H. Steier, Larry R. Dalton,
`Pei-Ming D. Chow
`D. H. Sutter, H . Schneider,
`S. Weisser, J . D. Ralston,
`E. C. Larkins
`Cangsang Zhao, Reinhart Engelmann
`
`S. Sanders, R. G. Waarts,
`D. G. Mehuys, D. F. Welch
`Yusuke Mori, lkuo Kuroda,
`Satoshi NakajimaTakatomoSasaki,
`Sadao Nakai
`Min-Cheol Oh, Sang-Yung Shin,
`Woi-Yon Hwang, Jang-Joo Kim
`. H. P. Lee, E. Ranalli, X. Liu
`
`Peler B. Nagy, Adnan H. Nayfeh
`
`David J. Smith, D. Chandrasekhar,
`B. Sverdlov, A. Botchkarev,
`A. Salvador, H . Morkoy
`D. Sander, A. Enders, J. Kirschner
`
`L. D. Zhu, J. Zhao, F. Wang,
`Peter E. Norris, G . D. Fogarty,
`B. Steiner, P. Lu, B. Kear, S. B. Kang,
`B. Gallais, M. Sinclair, D. Dimos,
`M. Cronin-Golomb
`A. A. Weimer, T. P. Thorpe,
`K. A. Snail, C. E. Merzbacher
`J . D. Prohaska, J . Li, J. S. Wang,
`A. H. Bartram
`Suneet Tuli, A. B. Bhattacharyya,
`D. Fournier
`A. Kozanecki, A. J. Wilson,
`B. J. Sealy, J. Kaczanowski,
`L. Nowicki
`
`Vizio EX1007 Page 0002
`
`

`

`1850 Relationship between self-organization and size of lnAs islands on
`lnP(001) grown by gas-source molecular beam epitaxy
`1853 Synthesis of oriented textured diamond films on silicon via hot
`filament chemical vapor deposition
`1856 High quality lnGaN films by atomic layer epitaxy
`
`SEMICONDUCTORS
`1859
`Improved thermal stability of AIGaAs-GaAs quantum well
`heterostructures using a " blocking" Zn diffusion to reduce column-Ill
`vacancies
`1862 Near-field optical beam induced current measurements on
`heterostructures
`1865 Growth of germanium-carbon alloys on silicon substrates by
`molecular beam epitaxy
`
`1868 High-power lnGaN single-quantum-well-structure blue and violet
`light-emiHing diodes
`1871 The fabrication of quantum wire structures through application of
`CCI4 towards lateral growth rate control of GaAs on patterned GaAs
`substrates
`
`1874 Photoluminescence studies of single submonolayer lnAs structures
`grown on GaAs (001) matrix
`
`1877 High aspect ratio submicron silicon pillars fabricated by
`photoassisted electrochemical etching and oxidation
`1880 Effects of electron cyclotron resonance plasma thermal oxidation on
`the properties of polycrystalline silicon film
`1883 Measurement of the minority carrier mobility in the base of
`heterojunction bipolar transistors using a magnetotransport method
`1885 Comparative analysis of the optical quality of single
`ln0.1Gao.sAs/A10.33Ga0•67As quantum wells grown by molecular beam
`epitaxy on (100) and (311) GaAs substrates
`1888 Photoluminescence and microstructure of self-ordered grown SIGel
`Si quantum wires
`
`1891 Eu-doped CaF2 grown on Si(1 00) substrates by molecular beam
`epitaxy
`
`1894 Minority carrier lifetime improvement by geHering In Si1 - xGex
`
`1896 Reduction of recombination current in CdTe/CdS solar cells
`
`1899 The electronic structure and energy level alignment of porphyrin/
`metal interfaces studied by ultraviolet photoelectron spectroscopy
`
`1902 Temperature dependence of the etch rate and selectivity of silicon
`nitride over silicon dioxide in remote plasma NFafCI2
`1905 Band filling at low optical power density in semiconductor dots
`
`1908
`
`Investigation of high-field domain formation in tight-binding
`superlattices by capacitance- voltage measurements
`1911 High quality single and double two-dimensional electron gases
`grown by metalorganic vapor phase epitaxy
`
`(Continued)
`
`A. Panchet, A. Le Carre, H. L'Haridon,
`B. Lambert, S. Salaun
`Qijin Chen, Jie Yang, Zhangda Lin
`
`K. S. Boutros, F. G. Mcintosh,
`J . C. Roberts, S. M. Bedair,
`E. L. Piner, N. A. EI-Masry
`
`M. R. Krames, A. D. Minervini,
`E. I. Chen, N . Holonyak, Jr.,
`J. E. Baker
`M. s. Unlu, B. B. Goldberg,
`W. D. Herzog, D. Sun, E. Towe
`J. Koiodzey, P. A. O'Neil, S. Zhang,
`B. A. Orner, K. Roe, K. M. Unruh,
`C. P. Swann, M. M. Waite,
`S. lsmat Shah
`Shuji Nakamura, Masayuki Senoh,
`Naruhito lwasa, Shin-ichi Nagahama
`Yong Kim, Yang Keun Park,
`Moo-Sung Kim, Joon-Mo Kang,
`Seong-11 Kim, Seong-Min Hwang,
`Suk-Ki Min
`Wei Li, Zhanguo Wang, Jiben Liang,
`Bo Xu, Zhanping Zhu, Zhiliang Yuan,
`Jian Li
`H. W. Lau, G. J. Parker, R. Greet,
`M. Holling
`Jung-Yeal Lee, Chui-Hi Han,
`Choong-Ki Kim, Bok-Ki Kim
`Y. Setser, D. Ritter, G. Bahir,
`S. Cohen, J . Sperling
`0 . Brandt, K. Kanamoto, M. Tsugami,
`T. lsu, N. Tsukada
`
`A. Hartmann, C. Dieker, R. Loo,
`L. Vescan, H. Luth, U. Bangert
`X. M. Fang, T. Chatterjee,
`P. J . McCann, W. K. Liu, M. B. Santos,
`W. Shan, J. J. Song
`B. R. Losada, A. Moehlecke,
`R. Lagos, A. Luque
`D. M. Oman, K. M. Dugan,
`J. L. Killian, V. Ceekala,
`C. S. Ferekides, D. L. Morel
`S. Narioka, H. Ishii, D. Yoshimura,
`M. Sei, Y. Ouchi, K. Seki,
`S. Hasegawa, T. Miyazaki, Y. Harima,
`K. Yamashita
`J . Staffa, D. Hwang, B. Luther,
`J. Ruzyllo, R. Grant
`P. Castrillo, D. Hassman, M.-E. Pistol,
`S. Anand, N. Carlsson, W. Seifert,
`L. Samuelson
`Z. Y. Han, S. F. Yoon,
`K. Radhakrishnan, D. H. Zhang
`H. C. Chui, B. E. Hammons,
`J . A. Simmons, N. E. Hartt,
`M. E. Sherwin
`
`Vizio EX1007 Page 0003
`
`

`

`1914
`
`Intensity-dependent energy and line shape variation of donor(cid:173)
`acceptor-pair bands In ZnSe:N at different compensation levels
`
`SUPERCONDUCTORS
`1917 Extended function of a high-Tc transition edge bolometer on a
`micromachined Si membrane
`
`1920 Deposition of high quality VBa2Cu30 7 _ . films on ultrathin (12 p.m
`thick) sapphire substrates for infrared detector applications
`
`1923 Generation of 24.0 Tat 4.2 K and 23.4 Tat 27 K with a high-temperature
`superconductor coil In a 22.54 T background field
`1926 Biomagnetic measurements using low-noise integrated SQUID
`magnetometers operating in liquid nitrogen
`1929 Correlation of critical current and resistance fluctuations in bicrystal
`grain boundary Josephson junctions
`1932 Determination of pinning strength of VBa2Cu30 7 _ 6 from magnetic
`stiffness measurements
`
`1935 Disorder and synchronization In a Josephson junction plaquette
`
`MAGNETISM
`1938 History dependent domain structures In giant-magnetoreslstive
`multi layers
`
`PAPERS IN OTHER FIELDS
`Ferroelectric phase transition temperatures of KTiOP04 crystals
`grown from self-fluxes
`
`1941
`
`COMMENTS
`1944 Comment on " Phase transformation of cobalt induced by ball
`milling" [Appl. Phys. Lett. 66, 308 (1995)]
`1945 Response to "Comment on 'Phase transformation of cobalt induced
`by ball milling'" [Appl. Phys. Lett. 67, 1944 (1995)]
`
`1947 CUMULATIVE AUTHOR INDEX
`
`P. Biiume, J . Gutowski, D. Wiesmann,
`R. Heitz, A. Hoffmann, E. Kurtz,
`D. Hommel, G. Landwehr
`
`H. Neff, J. Laukemper, G. Helie,
`M. Burn us, T. ,tieidenblut,
`W. Michalke, E. Steinbeiss
`A. Pique, K. S. Harshavardhan,
`J. Moses, M. Mathur, T. Venkatesan,
`J. C. Brasunas, B Lakew
`K. Ohkura, K. Sato, M .. Ueyama,
`Jun Fujikami, Y. lwasa
`M.S. Dilorio, K-Y. Yang, S. Yoshizumi
`
`A. Marx, U. Fath, L. Alff, R. Gross
`
`Be ate Lehndorff,
`Hans-Gerd Kurschner,
`Bernhard Lucke
`A. S. Landsberg, Y. Braiman,
`K. Wiesenfeld
`
`H. T. Hardner, M. B. Weissman,
`S. S. P. Parkin
`
`N. Angert, M. Tseitlin, E. Yashchin,
`M. Roth
`
`G. Mazzone
`
`J. Y. Huang, Y. K. Wu, H. Q . Ye
`
`A publication of the American Institute of Physics, 500 Sunnyside Blvd., Woodbury, NY 11797-2999
`
`Vizio EX1007 Page 0004
`
`

`

`APPLIED
`PHYSICS
`LEITERS
`
`CODEN: APPLAB
`ISSN: 0003-6951
`
`Editor
`Nghi Q . Lam
`Argonne National Laboratory
`Argonne, IL
`
`Consulting Editor
`Gilbert J. Perlow
`
`Associate Editors
`at Argonne National Laboratory
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`Samuel D . Bader
`Alan R . Krauss
`Jules Routbort
`David S . Kupperman
`Linda Young
`F. Paul Mooring
`
`Editorial Board
`Term ending 31 December 1995
`Ulrich Giisele (Max Planck lnst., Halle, Germany)
`W illiam L. J ohnson (Caltech , Pasadena, CA)
`William F. K rupke (Lawrence Livermore Lab, CA)
`
`Term ending 31 December 1996
`Gene F. Dresselhaus (MIT, Cambridge, MA)
`Allen M . Goldman (Univ. Minnesota, Minneapolis, MN)
`Klaus H . Pioog (Paul Drude lnst., Berlin, Germany)
`Robert Sinclair (Stanford Univ., Stanford, CA)
`
`Term ending 31 December 1997
`Federico C a passo (AT&T Bell Labs, Murray Hilt, NJ)
`Esther M. Conwell (Xerox. R ochester, NY)
`C. Y. Fong (Univ. of California, Davis, CA)
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`Vizio EX1007 Page 0005
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`

`

`High-power lnGaN single-quantum-well-structure blue and violet
`light-emitting diodes
`Shuji Nakamura,a> Masayuki Senoh, Naruhito lwasa, and Shin-ichi Nagahama
`Department of Resttarch and Dewlopment, Nichio Cltttmicallndustrtes. Lid., 49/ Oko, Kami1111ko, Anan.
`Tokushiuut 774, Japan
`
`(Received 28 March 1995; accepted for publication 3 1 J uly 199-')
`
`High-power blue and violet light-cmiuing diodes (LEOs) based on Ill - V nitrides were grown by
`metalorganic chemical vapor deposition on sapphire substrates. As an active layer, the LnGaN
`single-quantum-well-structure was used. The violet LEOs produced 5.6 mW at 20 rnA. with a ~harp
`peak of light output at 405 nm, and exhibited an external quantum efficiency of 9.2%. The blue
`LEDs produced 4.8 mW at 20 rnA and sharply peaked a t 450 nm, corresponding to an external
`quantum efficiency of 8.7%. These values of the output power and the quantum efficiencies arc the
`highest ever reported for violet and blue LEOs. © / 995 American lnstifll(e of Pln·sics.
`
`Much research has been conducted on htgh-brightne s
`blue light-emitting diodes (LEDs) and laser diodes (LDs) for
`u,c in full-color displays. full-color indicators. and light
`sources for lamps with the characteri\llcs of high efficiency.
`high reliability. and hig h ~peed. For the. e purpose~. II- VI
`materials such as ZnSe.1 SiC,2 and m- V nitride semicon(cid:173)
`ductors s uch as GaN3 have been inve~tigated intensively for
`a long time. However, it has been impossible to obtain high(cid:173)
`brightness blue LEDs with brightness over I cd. As II - VI
`based materials. ZnMgSSe-, ZnSSe-, and ZnCdSe-based ma(cid:173)
`terials have been intensively studied for blue and green light(cid:173)
`emitting devices, and much progress ha~ been achieved re(cid:173)
`cently o n green LED~ and LD~. The recem situation
`regarding performance of II- VI green LEOs is that the out(cid:173)
`put power is 1.3 mW at 10 rnA and that the peak wavelength
`is 512 nm.~ When the peak wavelength shortens to the blue
`region, the output power decreases dramatically to about 0.3
`mW at 489 nm.~ The lifetime of 0 -VI-based light-emiuing
`devices is
`till short. which prevents the commercialization
`of 11- YI-based devices at present. SiC is another wi\e band(cid:173)
`gap material for blue LEDs. Current output power of SiC
`blue LEOs is onl y between 10 and 20 ~J.W because it is an
`indirect band-gap material?
`On the other hand. there are no uitable substrates for
`Ill- Y nitride growth without sapphire considering its high
`growth temperature and the cost of the substrate although the
`sapphire has a large lattice mismatch between GaN and sap(cid:173)
`phire. Despite this large lattice mismatch. recent research on
`Ill- Y nitrides has paved the way for the realization of high(cid:173)
`quality crystals of AJGaN a nd JnGa , a nd p-type conduction
`in AIGaN.s- s Moreover. the hole-compen~ation mechanism
`of p -type AIGaN has been elucidated.9 High-power blue and
`blue-green LEDs with an output power over 1 mW have
`been achieved by u ing these techniques and are now com(cid:173)
`11 Although
`mercially available. 10
`these
`lnGaN/AIGaN
`·
`double-heterostructure (OH ) LEDs produce a high-power
`light output in the blue and blue-green region~. they have a
`broad emission spectrum [full width at half-maximum
`(FWHM)=70 nm) with the lig ht output ranging from the
`
`" Eiectmn•c mail· \huji@nichia.co.jp
`
`violet to the yellow-orange ~pectral region. This broad spec(cid:173)
`trum. which result:- from the intentional introduction of Zn
`into the loGaN active region of the device to produce a deep(cid:173)
`level emis!-ion peaking at 450 nm, makes the output appear
`whitish-blue. when the LED is viewed with the human eye.
`Therefore, blue LEOs. wh1ch produce a sha rp blue e mission
`at 450 nm with a narrow FWHM. have been desired for
`application to full-color LED displays. For this purpose, vio(cid:173)
`le t LEOs with a narrow spectrum (FWHM = 10 nm) at a peak
`wavelength of 400 nm originating from the band-to-band
`emission of loGaN were reported. 12 However, U1e output
`power of these vio let LEOs was only about I mW, probably
`due to the formation of misfit dislocation in the thick loGaN
`active layer (about 1000 Al by the stress introduced into the
`lnGaN active layer due to lauice mi!>match. and the differ(cid:173)
`e nce in themtal expansion coefficients between the lnGaN
`active layer and AIGaN cladding layers. When the thicknes~
`of the loGaN active layer become~ mall, the clastic ~train b
`not relieved by U1e forn1ation of misfit di~location and that
`the crystal quality of the lnGaN active layer improves. We
`reported the high-quality lnGaN multiquantum-well stntcturt:
`(MQW) with the 30 A well and 30 A barrier layers." Here.
`we describe the single quantum-well stmcturc (SQW) blue
`LEOs which have a thin lnGaN active layer (about 20 A) in
`order to obtain high-power blue e mi s~ion with a narrow
`e mission spectrum.
`111- Y nitride films were grown by the two-flow metal or(cid:173)
`ganic chemical vapor deposition (MOCYD) method. Details
`of the two-How MOCVD are described in other papers.14
`The growth was conducted at atmo~pheric pressure. Sapphire
`with (000 I) orientation (c face), which had a 2 in. diameter.
`was u ~ed as a sub tra te. The growth conditions of each layer
`are described in other papers. 10•11 In comparison with preVI(cid:173)
`ous lnGaN/AIGaN DH LEDl>, the major difference is that the
`lnGaN active layer become~ a thin undoped lnGaN layer.
`The blue LED device structures (Fig. I) consiMs of a
`300 A GaN buffer layer grown at a
`low temperature
`(550 °C), a 4 IJ.m thick layer of 11-type GaN:Si. a 1000 A
`thicklayer of n-type A1o; Gli(, 7N:Si. a 500 A thick layer
`of n -type lnomGao.9sN:Si. a 20 A thick active layer of un(cid:173)
`l no.2Gao 8N. a 1000 A U1ick
`doped
`layer of p-type
`Alo.JGao.7N :Mg. and a 0.5 ~J-Ill thick layer of {Hype GaN:Mg .
`
`1868
`
`Appl. Phys. Lett. 67 (13), 25 September 1995
`
`0003-6951/95/67( 13)/186813/$6.00
`
`C 1995 American lnslltule of PhySICS
`
`Vizio EX1007 Page 0006
`
`

`

`n~e
`
`14
`
`12
`
`~
`
`10
`~
`.§. 8
`~ = ... 6
`:; ... :;
`
`0
`
`4
`
`--
`
`p·electrode
`
`p-GaN
`p·Aio.3 GauN
`1
`ln.uGau N
`n-lo 0.01G....,N
`n·AI0.JGa1.7N
`-
`n-GaN
`GaN buller layer
`
`Sapphire substrate ,_
`
`FIG. I. The StniC!Ure of SQW blue LED.
`
`2
`
`The active region forms a SQW structure consisting of a 20
`A lno.!G~to.sN well layer sandwiched by 500 A 11-type
`In0.01Gao.98N and 1000 A p-type A10.3Gao.7N barrier layers.
`In violet LEOs, the active layer is tn0.09Gao.9N.
`Fabrication of LED chips was accomplished as follows.
`The surface of the p-type GaN layer was partially etched
`until then-type GaN layer was exposed. Next. a Ni/Au con(cid:173)
`tact was evaporated onto the p-type GaN layer and a Til AI
`contact onto the n-type GaN layer. The wafer was cut into a
`rectangular shape (350 ,um X 350 ,urn). These chips were set
`on the lead frame, and were then molded. The characteristics
`of LEOs were measured under direct current (dc)-biased con(cid:173)
`ditions at room t~mperature.
`Figure 2 shows the e lectroluminescences (EL) of the
`SQW blue LEOs in comparison with the previous Zn-doped
`lnGa.N/AIGaN DH blue LEOs ut forward current of 20 rnA.
`The peak wavelengths of both LEDs are 450 nm. The
`FWHM of the EL spectrum of the SQW blue LEDs is about
`25 nm. while that of DH LEOs is about 70 nm. The peak
`wavelength and the FWHM of SQW LEOs are almost con(cid:173)
`stant when the forward current is increased to I 00 rnA. On
`the other hand. the peak wavelength of DH LEOs becomes
`shorter with increasing forward current and a band-to-band
`emission (around 385 nm) appears under a high-current in(cid:173)
`11 In the SQW blue LEDs. the active
`jection condition. 10
`•
`layer is an In0.2Gao.8N whose band-edge emission wave(cid:173)
`le ngth is 420 nm under the stress-free. 12 On the other hand,
`the emission peak wavelent:,rth of SQW b lue LEOs is 450 nm.
`The energy difference between the peak wavelength of the
`ELand the stress-free band-gap energy is approximately J 90
`
`For ward Current (rnA)
`
`FIG. 3. The OUipUI power of (a) SQW violet LED. (b) SQW blue LED, and
`(c) DH blue LED as a func1ion of the forward current.
`
`meV. In order to explain this band-gap narrowing of the
`ln0.2Gao.8N active layer, the quantum size effects, the exciton
`effects (Coulomb effects correlated to the electron-hole pair)
`of the active layer. and the strained effects by the mismatch
`of the lattice and the difference in thermal expansion coeffi(cid:173)
`cients between well layer and barrier layers must be consid(cid:173)
`ered. Among these effects, the tensile stress in the active
`layer caused by the thermal expansion coefficient difference
`between well layer and barrier layers is probably responsible
`for the band-gap narrowing of the lnGaN SQW structure.
`The output power of the SQW LEOs and the DH blue
`LEOs is shown as a function of the forward current under de
`in Fig. 3. The output power of the SQW LEOs and that of the
`DH LEOs slightly increases sublinearly up to 40 rnA as a
`function of the forward current. Above 60 rnA, the output
`power almost saturates, probably due to the generation of
`heat. The output power of the SQW violet LEOs is 2.8 mW
`at 10 rnA, and 5.6 mW at 20 rnA. which is about twice as
`high as that of the DH blue LEOs. The external quantum
`efficiency is 9.2% at 20 rnA. The output power of SQW blue
`LEDs with a peak wavelength of 450 nm is 4.8 mW at 20
`mA and the external quantum efficiency is 8.7%.
`A typical example of the/- V characteristics of the SQW
`blue LEOs is shown in Fig. 4. The forward voltage is 3.1 V
`
`100
`
`,S
`!'
`so
`
`~ .. . ..;
`·~ c :: .:
`.J "'
`
`0
`
`R.T.
`U:lOmA
`
`350
`
`600
`
`650
`
`Wavelength (nm)
`
`Y: SmA/div.
`
`FIG. 2. Electroluminc~cencc spcclra of (a) SQW blue LED and (b) DH blue
`LED at a forward curren1 of 20 mA.
`
`FIG. 4. Typical / - V characteristics of SQW blue LED.
`
`X: l V/div.
`
`Appl. Phys. Lett., Vol. 67, No. 13. 25 September 1995
`
`Nakamura et al.
`
`1869
`
`Vizio EX1007 Page 0007
`
`

`

`at 20 rnA. This forward voltage is the lowest value ever
`reported for m- v nitride LEDs.
`In summary. high-power lnGaN SQW blue and violet
`LEDs were fabricated. The output power of the violet LEOs
`wa~ 5.8 mW and the external quantum efficiency was as high
`as 9.2% at a forward current of 20 rnA at room temperature.
`The peak wavelength and the FWHM were 405 and 20 nm.
`respectively. and those of blue LEOs were 450 and 25 nm,
`respectively. Such LED performances of quanrum well struc(cid:173)
`tures will pave the way for the realization of blue LDs based
`on Ill- V nitride materials in the near future.
`
`1 W. Xie, D. C. Grillo, R. L. Gunshor, M. Kobayashi, H. Jeon, J. Ding, A. V.
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`Series No. 137 (American ln>titute of Ph) $icS. Woodbury. NY. 1994). p.
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`11 S. Nakamuru, T. Mukai . and M. Senoh, J. Appl. Phys. 76, 8 189 ( 1994)
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`Phys. 74, 3911 ( 1993).
`14 S. Nakamura, Jpn. J. Appl. Phy,. 30, 1620 (1991 ).
`
`1870
`
`Appl. Phys. Lett .• Vol. 67. No. 13, 25 September 1995
`
`Nakamura et a/
`
`Vizio EX1007 Page 0008
`
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