Chapter 3 - Photoluminescence in GaN and InGaN and their applications in photonics

Abstract

Photoluminescence and time-resolved spectroscopy of gallium nitride (GaN)- and indium gallium nitride (InGaN)-based materials and devices are discussed in this chapter. The chapter discusses the results obtained in various studies of the photoluminescence properties of GaN and related materials. The experimental techniques covered in the chapter include optical absorption, photoreflection (PR), modulation spectroscopy, spectroscopic ellipsometry, photoluminescence (PL), time-resolved PL, micro-PL, cathodoluminescence, pump-probe spectroscopy, femtosecond spectrally resolved and time-resolved degenerate four-wave mixing, second harmonic generation, laser-induced gratings, and quantum beats. The development of large area single-crystal growth of GaN may provide the ultimate solution to the problem of lattice mismatch. GaN and other III–V nitrides have been realized as potential candidates in photonics. Light emitting diode (LEDs) and semiconductor lasers that emit in a variety of wavelengths from blue to yellow are now commercially available. They are being used in full-color displays and traffic lights. LEDs that emit various colors are also substitutes for traditional fluorescent lamps and can be used in homes and shops. The market for LEDs is huge. Blue LEDs also find applications in laser printers and underwater optical communications for the Navy. In the near future, it is possible to develop digital video disks in which InGaN and GaN lasers are used.