Low-bandgap nitrides: Issues and applications

Nitrogen incorporation in Ill-V compounds reduces rhe bandgop. changes the conducrion band offiet, and even changes the band stmcture. Here w,e report the use of low-bandgap GaInNAs as rhe base of a heferojuricrion bipolar tramistor (HBr). which exhibits a lower turn-on voltage than HBTs with the usual GnAs base. InNAsP/GalnAsP quantum wells grown on InP are superior for longwavelenglh microdisk lasers. as compared Io GalnAs/GalnAsP quanruni wells, because of the larger conduction band ofset. Incorporating N into GalnP barriers in a GaAs quantum well is shown to lower the conduction band @et, and GalnNP/GaAs could be potentially ideally suited for npn HBTs. Incorporating a small amount o f N in G a N Z , alloys leads to a direct bandgap behavior of GaNP, and red light-emitting diodes grown directly on (100) GnP substrates have been fabricated.