Page 30 - Demo PravySoft Ezine

NET ELECTRONICS MODULE I

Figure 1. 83: Various mechanisms of electron-hole recombination in
semiconductors. (a) Interband transitions (b) Band to localized
defect states transitions (c) Intraband transitions. ....................... 297

Figure 1. 84: pn junction LED at (a) equilibrium and (b) forward bias.
...................................................................................................... 298

Figure 1. 85: GaAs based (a) homojunction and (b) heterojunction.
...................................................................................................... 299
Figure 1. 86: Double heterostructure based LED. (a) Device
structure, with a single pn heterojunctions and a p − p isojunction

(b) Equilibrium band diagram, with the built-in potential at the pn
junction (c) In forward bias electrons and holes are injected in the
Ga ................................................................................................. 300

Figure 1. 87: Double heterostructure device structure with (a)
PravySoft Ezine demo
PravySoft Ezine demo
surface or (b) edge emission. ........................................................ 302
Figure 1. 88: Theoretical line width in a LED. ................................ 305
Figure 1. 89: (a) PL spectrum from a GaAs LED, at two different

temperatures. (b) Plot of the photon energy vs. temperature ..... 306
Figure 1. 90: Device structure of an OLED .................................... 314
Figure 1. 91: Liquid Crystal Phases................................................ 318

Figure 1. 92: Basic Components of LCD Display ............................ 319
Figure 1. 93: Transmissive LCD Display Working .......................... 320
Figure 1. 94: Reflective LCD Display Working ............................... 322
Figure 1. 95: Positive and Negative LCD Displays ......................... 323

Figure 1. 96: Honeycomb pattern of Graphene's atoms .............. 348