The AlGaInP/AlGaAs Material System and Red/Yellow LED

In this chapter, AlGaInP and AlGaAs alloy compound semiconductor system was reviewed for solid-state lighting application, including their lattice and bandgap structure, heterojunction, and quantum well properties. LEDs based on AlGaInP quantum well and GaAs substrate operating in the red, orange, and yellow visible spectrum were discussed including the major classes of AlGaInP device structures, such as GaP-absorbing substrate LEDs enhanced by distributed Bragg reflectors (DBRs), transparent-substrate LEDs (TS-LEDs), thin-film LEDs (TF-LEDs), and GaP window/current-spreading layer. AlGaInP/AlGaAs material MOCVD epitaxy and LED chip processing technology were introduced briefly.