EXHIBIT 1010
`
`E. Fred Schubert, Light Emitting Diodes,
`(Cambridge University Press 2003)
`
`(“Schubert”)
`
`

`
`LIGHT-EMITT|TNG DIoDES
`
`I I
`
`E. FRED SCHUBERT
`I
`Renss elae r Polyt ebhntc I nstitute
`
`I :i
`
`II:III j III III IIt
`
`lII
`I
`
`CervrBRrDGE
`{JhITVERSITY PRESS
`
`I I I
`
`IIt I
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 1
`
`

`
`PUBLIS}IED BY THB PRESS SYNDICATB OF THE UNIVERSITY OF CAMBRIDGB
`The Pitt Building, Trumpington Street, Cambridge, United Kingdom I
`CAMBRIDCE UNIVEN'SITY PRESS
`The Edinburgh Building, Cambridge CB2 2RU, UK
`40 West 20rh Street, New York, NY l00l l-4211. USA
`4?7 Williamstown Road, Port MElbourne, VIC 3201, Ausralia
`Ruiz de Alarc6n 13, 28014 Madrid, Spain
`Dock House, The Waterfront, Cape Town 8001 , South Africa
`hnP : //www. c ambrid ge' org
`
`I
`
`@ E. Fred Schubert 2003
`This book is in copyright. Subject to $tarutory exception
`and to the provisionJ of rclevant collective licensing agreements,
`no rlproducdon of any part may take_place withour
`ths writtcn permission of Carnbridge University Press'
`First Published 2003
`Reprinted with conections 2005
`Reprinted 2005
`hinted in the United Kingdom at the University Press, Cambridge
`Typeface Times I 1/14 pt
`'systim I$TIf, 2s [rsJ
`A catalog rvcord for this book is avaihble fiom the British Library
`Library of congress cataloging in Publication data
`ISBN 0 521 82330 7 hardback
`ISBN 0 521 53351 I PaPerback
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 2
`
`

`
`III III
`
`5 LED baiics: optical propcrticr
`
`IiI
`
`Polymer 0. = 41 .8o .
`
`t
`
`Wtt{t improvement can be attained if a planar GaAs LED is encapsulated in a transpafent
`i
`polymef of refractivc index 1.5, if the reflection at the polymer-air interfacc is neglected?
`Soltition:
`ICritical angle for total internal reflection:
`IG"4t 0. - t?.1 o
`GaN 0, = 23.6o
`IFra{tion of light that can escape:
`ICar{s 2.21 Vo
`Polymer 12J Vo .
`GaN 4.I8 Va
`Implrovement of the GaAs planar LED due to polymer encapsulation: 232 Vo.
`'l
`II
`5 A The hmbertian emission Pafrern
`The indlx conrrast between the light-cmitting material and the sunounding material leads to a
`I
`I
`non-$oFoplc emrssron pattern. For high-index light-emining materials with a planar surface, a
`.l
`tl*U"tt!- cmission pattcrn is obtained. Figure 5.4 illusuates a point-like light source located a
`,
`short diltancc below a semiconductor-air interface. Consider a light ray emitted from the source
`at an ingle 0 with respect to the surface normal. The light ray is refracted at the
`I
`I
`semicorlductor-air interface and the refracted light ray has an angle O with respcct to the surfacc
`I
`normallThc two anglcs arc rclatcd by Snell's law, which, for small angles of Q' can be written as
`I
`F, 0 = fiatu sin@ '
`
`(s.2s)
`
`Light eiritted into the angle d{ in the semiconductor is cmittcd into the angle dO in air as shown
`in Fig. i.C (a). Differentiating thc equarion with respect to O and solving the resulting cquation
`for diD |ields
`
`do = + 4oO.
`fr,,r cos(D
`requires that the optical power emitted into the angle dQ in the
`Porue, f "onservation
`I
`scmico{auctor be equal to the optical power emined into the angle dO in air, i-e.
`
`(5.26)
`
`I
`
`/s d4 r /ri, &{sir
`
`(5.27)
`
`92
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 3
`
`

`
`where /, and /"i, are the tight intensities (
`respectively. Owing to the cylindrical
`element shown in Fig. 5.4 (b). The area
`
`Iarnbe rtian c mission Patten
`
`scmiconductor and air,
`rn we choose the area
`
`Muit
`
`(5,28)
`
`rl|
`
`!*-
`
`rsin0
`
`Yra-Light source
`
`Using Eqs. (5.26) and (5 .27) yields
`
`dAli, = ?nr| #
`
`._
`'lrl
`cosO 0d0
`
`Sirnilarly, the surface elernent in the semiconductor is given by
`
`d4 i= Znr sin Q r dS e'
`
`I2r\rz 0 d0
`
`(s.2e)
`
`(5.30)
`
`The light intensity in the semiconductor at a distance r f,rom the light source is given by the total
`source power divided by the surface area of a sphere witfr radius r, i'e'
`
`t
`fq=
`
`D
`t SOUfCe
`4n r2
`
`(5.3 1)
`
`93
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 4
`
`

`
`ttlIfI
`
`5 LED basics! optical ProP€rties
`
`t II
`
`The light ihtensity in air can then be inferred from Eqs.
`obtains thellambertian emission pattern given by
`
`(5 .27), (5 .29), (5.30), and (5 .3 I ). One
`
`/x11 =' 3ry +coso
`4nr2 Rs
`
`(5.32)
`
`Thc laurbel,tian emission pattern follows a cosine dependence on the angle tD' The intensity is
`highest foi emissiOn normal to the semiconductor surface, i,e. for <D= 0o. At an angle of
`O = 60o, thb intcnsity decrcases to half of its maximum value. The lambertian emission pattern is
`shown schjmadcally in Fig.5.5.
`
`I
`
`ffiffi
`(b, v
`
`(a)
`
`Serni-l
`conductbr
`
`Light-
`emitting
`re$on
`
`Planar LED
`
`(c) M
`
`Hemispherical LED
`
`Parabolic LED
`
`.iti-'i
`
`..:+\
`;T-i--'/"\
`-l-i--J'-*
`
`i-/{',*i-w \ >l-
`
`t.
`
`jt -\-
`- ttr,i-'l--
`)',,-
`l,rMr
`t,. --
`X".. \ -i-
`,).)t"i'f
`ittji
`1-+--fWi
`I Dlonar I trn
`;{'.':,jr'r
`lt
`Y"'\-1';;;til-ol fi--
`1.0 | o.g 0.6 0.4 0.2 0.0 0,2 0.4 0.6 0.8
`Figl 5.S, Light-emitting diodes with (a) planar, (b)_hemispherical, and (c) parabolic
`strdaces. (d) Far-field patterns of the different types of LEDs. At an angle of O = 60o, the
`lanilUrttitn emission p.rc* decteases to 50 To ofits maximum
`its maximum value occurring at O = 0o
`ThA three emissioo patterns af,e normalized to unity intensify at O = 0o.
`
`94
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 5
`
`

`
`5.4 The lambertian enission pa,ttern
`
`Several other surface shapes are also shown in Figi.5.5. These non-planar surfaces cxhibit
`various emission pattems. An isotropic emission patbr,l is obtained for hemispherically shapcd
`LEDs, which havc the light.emitting rcgion in the cqLter of the sphere. A strongly dircctcd
`emission pattern can be obtained in LEDs witfr parab8[cally shaped surfaces. However, both
`hcmispherical as well as parabolic surfaces arc difficult io fabricate.
`The rotal power emitted inlo air can be calculated b! integrating the intensity ovcr the entire
`hemisphere. The total power is then given by
`
`I t
`
`,
`
`jl
`
`Pair = /;:ro
`By using the lambertian emission pattern for l* ini Eq. (5.33) and using cos O sin O =
`(Llz) sin (2 @), the integral can be calculated to yield
`ffi
`
`(5.33)
`
`(5.34)
`
`IIIII
`
`2n rsin@ rdO .
`
`lr
`
`I I
`
`/air
`
`D.
`I alr
`
`G
`
`Prour.,
`
`421
`
`This result is identical to Eq, (5,24). This is not surprising because the light power that escapes
`from the semiconductor (Pcsc.p.) must be identical to the power in air (P.i,).
`[e semiconductor-air interface has
`In the calculation above, Fresnel reflection at th:e semi
`t.
`neglected. At nonnal incidence, the Fresnel power transmittance is given by
`
`I,
`
`t
`
`T = r-^
`
`.
`
`=
`
`(Es nap)'
`l-l\ns + f,air I
`
`4. [r E"it
`(G + fr*)z
`
`(5.35)
`
`Fresnel reflection losses must be taken into account in a in9otous calculation.
`,."r"r*;6ya-ntti coupling efficiency. Considir a GaAs LED with a point-like light-
`emitting region located in close proximity to the planarlGaAs LED surface, An optical fibd has
`t"
`an acceptance angle of l2o in air. What fraction of the iight emitted by the active region can be
`couplcd into the fibcr? Assume a GaAs refractive indei of fr,= 3'4' Neglect Fresnel reflection
`losses at the semiconductor-air and air-fiber intcrfaces. i
`Solution: The acceptance angle in the semiconductol is obtained from Snell's law and is 3,5o
`
`95
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 6
`
`

`
`II
`
`Thus 0.093lEo orthe power emitted by the active region can be coupled into the fiber'
`
`Fig. 5.6. (a) LED without and
`(b) with dome.shaPed epoxy
`encapsulant. A larger escaPe
`angle is obuined for the LED
`with an epoxy dome. (c)
`Calculated ratio of tight ox'
`traction efticiencY ernitted
`througb the top surface of a
`planar LED with and without an
`epoxy dome. The refractive
`indices of typical ePoxies range
`betwocn I .4 and 1.8 (adoPted
`from Nueee et a1.,1959).
`
`Refractive indcx of encapsulating epoxy E' (')
`
`l0
`
`II 7 6 5 4 3 2 1
`
`I
`
`o
`{Jf,l|.'
`
`Li.-6'F
`hxoat€
`>\otrt)o
`
`kr{.4
`0)
`o.s
`
`aSEttxrrl
`
`55 EpoxY enca4sulants
`The fight "i*"rioo cfficiency can be enhanced by using domc'shaped encapsulants with a large
`refractive ifrOe*, {s a result of the encapsulation, the angle of total internal reflection tbrough the
`top surfaci of thc scmiconductor is increased. It follows from Eq. (5.22) that the ratio of
`l
`exhaction lmrirn.y with and without cpoxy encapsulant is given by
`I - cos Qc,epoxy@
`r-:no*T =
`
`I
`
`Tlair
`
`(5.36)
`
`and 0,..o is the critical angle for total internal reflection at the semiconductor-cpoxy
`where
`0
`wne
`.iJondocto.-air interfacc, respectively. Figure 5.6 shows the calculatcd ratio of the
`o sen
`and st
`and
`ionlefficicncy with and without atr epoxy domc. Inspcction of the figure yields that the
`oni
`tractir
`extr
`extrac
`o"yfot" typical scmiconduclor LED increases by a factor of 2 -3 upon encapsulation with
`icien
`effi
`efficie
`xy [raving a refractive index of 1 .5.
`an(
`epox
`an ep(
`irlset or rig. 5.6 (b) shows that light is incident at an angle of approximately g0o at the
`,riJ,
`TI
`The
`interface due to the dome-shape of the epoxy.Thus, total internalreflection losses do
`. [.
`ePox!
`,OXY-i
`-alfr I
`ePa
`orirt tt " epoxy_air interfacc. Besides improving the external effrciency of an LED, the
`not o(
`)t occ
`not
`
`Il
`
`I
`
`Kingbright Elec. Co. Ltd., Kingbright Corp., SunLED Corp.,
`Kingbright Co. LLC, SunLED Co. LLC and Sunscreen Co. Ltd.
`Exhibit - 1010 Page 7