Light-Emitting DiodesCambridge University Press, 15 mai 2003 - 313 pages Light emitting diodes (LEDs) are devices that are used in a myriad of applications, such as indicator lights in instruments, signage, illuminations, and communication. This graduate textbook covers all aspects of the technology and physics of infrared, visible-spectrum, and white light-emitting diodes (LEDs) made from III-V semiconductors. It reviews elementary properties of LEDs such as the electrical and optical characteristics. Exercises and illustrative examples reinforce the topics discussed. |
Table des matières
LXVII | 166 |
LXVIII | 167 |
LXIX | 171 |
LXX | 173 |
LXXI | 174 |
LXXII | 178 |
LXXIII | 180 |
LXXIV | 183 |
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| 107 | |
XLVII | 112 |
XLVIII | 114 |
L | 118 |
LI | 119 |
LII | 123 |
LIII | 128 |
LIV | 131 |
LV | 135 |
LVI | 136 |
LVII | 138 |
LVIII | 139 |
LIX | 140 |
LX | 147 |
LXI | 148 |
LXII | 149 |
LXIII | 150 |
LXIV | 155 |
LXV | 160 |
LXVI | 163 |
LXXV | 187 |
LXXVI | 191 |
LXXVII | 192 |
LXXVIII | 194 |
LXXIX | 198 |
LXXX | 199 |
LXXXI | 209 |
LXXXII | 211 |
LXXXIII | 213 |
LXXXIV | 215 |
LXXXVI | 216 |
LXXXVII | 219 |
LXXXVIII | 222 |
LXXXIX | 226 |
XC | 229 |
XCI | 231 |
XCIII | 234 |
XCIV | 236 |
XCV | 240 |
XCVI | 242 |
XCVII | 243 |
XCVIII | 245 |
XCIX | 247 |
C | 250 |
CI | 252 |
CII | 253 |
CIII | 254 |
CIV | 255 |
CV | 257 |
CVI | 267 |
CVII | 268 |
CVIII | 271 |
CIX | 273 |
CX | 276 |
CXI | 277 |
CXII | 278 |
CXIII | 279 |
CXIV | 281 |
CXV | 283 |
CXVI | 287 |
CXVII | 288 |
CXVIII | 290 |
CXIX | 291 |
CXX | 293 |
CXXI | 294 |
CXXII | 295 |
CXXIII | 297 |
CXXVI | 299 |
CXXVII | 301 |
CXXVIII | 305 |
CXXIX | 309 |
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Expressions et termes fréquents
active region AlGaAs AlGaInP AlGaInP LED AlGaInP/GaAs angle Appl bandgap bandgap energy blue calculated carrier concentration carrier lifetime chromaticity coordinates chromaticity diagram color-rendering color-rendering index confinement layer Craford current-spreading layer device diffusion dislocations distributed Bragg reflector doped double heterostructure electroluminescent electron and hole emission spectrum emitters enhancement epitaxial epoxy equation external quantum efficiency extraction efficiency GaAs substrate GaAsP LEDs GaInN/GaN given green LEDs heterostructure high-brightness Holonyak III-V injection interface laser lattice constant LEDs emitting Lett light source light-emitting diodes linewidth lm/W luminescence luminous efficiency material system microcavities minority carrier non-radiative recombination optical fiber optical mode density optical power p-n junction p-type phosphor photon Phys quantum efficiency R₁ RCLED red LEDs refractive index Schubert E. F. semiconductor shown in Fig spectral spontaneous emission surface recombination thickness top contact total internal reflection transparent wavelength white LEDs white light window layer
Fréquemment cités
Page 178 - Structures Spontaneous emission implies the notion that the recombination process occurs spontaneously, that is without a means to influence this process. In fact, spontaneous emission has long been believed to be uncontrollable. However, research in microscopic optical resonators, where spatial dimensions are of the order of the wavelength of light, showed the possibility of controlling the spontaneous emission properties of a light-emitting medium. The changes of the emission properties include...
Page 7 - During an investigation of the unsymmetrical passage of current through a contact of carborundum and other substances a curious phenomenon was noted. On applying a potential of 10 volts between two points on a crystal of carborundum, the crystal gave out a yellowish light.
Page 89 - The material dispersion in optical fibers limits the "bit rate X distance product" achievable with LEDs. The spontaneous lifetime of carriers in LEDs in direct-gap semiconductors typically is of the order of 1-100 ns depending on the active region doping concentration (or carrier concentrations) and the material quality. Thus, modulation speeds up to 1 Gbit/s are attainable with LEDs. A spectral width of 1.8kT is expected for the thermally broadened emission. However, due to other broadening mechanisms,...
Page 207 - T)ex is the device external quantum efficiency, h is the Planck constant, c is the velocity of light, e is the electronic charge, and J is the applied current density. These values can be increased by increasing T)ex and decreasing pixel electrode area.
Page 179 - Both publications reported an emission line narrowing due to the resonant cavities. RCLEDs have many advantageous properties when compared with conventional LEDs, including higher brightness, increased spectral purity, and higher efficiency. For example, the RCLED spectral power density at the resonance wavelength was shown to be enhanced by more than one order of magnitude [18, 19].
Page 119 - High-index \ / \^ y \^x \X semiconductor reflection is only 17°. Thus, most of the light emitted by the active region is trapped inside the semiconductor. The light-escape problem has been known since the 1960s. It has also been known that the geometrical shape of the LED die plays a critical role. The optimum LED would be spherical in shape with a point-like light-emitting region in the center of the LED. Light emanating from the point-like active region is incident at a normal angle at the semiconductor/air...