ABSTRACT
Interest in III-N-V compound semiconductors has increased recently because of the discovery that only a small amount of nitrogen incorporation (=2%) in conventional GaAs-and InP-based III-V compounds results in very large band-gap bowing [1, 2]. Hence, these materials are also called "dilute nitrides" or "low-band-gap nitrides." As described in Chapter 2, for GaN,Asi,, the band anticrossing model describes the repulsion of the GaAs host conduction band and the nitrogen localized states, which are in resonance with the conduction band. Thus, the bandgap bowing is a result of the downward movement of the conduction band [3]. Band-gap lowering allows 1.34tm light emission at room temperature from Gai _yInyN„Asi_x/ GaAs quantum wells (QWs), with y usually about 0.3. Chapters 10 and 13 describe the latest results in GaInNAs 1.3-gm edge-emitting and vertical-cavity surface-emitting lasers (VCSELs). In this chapter, we show that GaInNAs and GaInNP, both grown on GaAs (001) substrates, can also be beneficial to heterojunction bipolar transistors (HBTs).
