Gallium nitride based electronics and opto-electronics

The benefit provided by optoelectronic applications of gallium nitride is immeasurable and, contrary to electronics applications, it provides an unique solution not merely a better one. This is because of the wide range of tunable and direct band gaps available in the (Al,Ga,In)N family from the deep UV (AlN; 6.2 eV) to values commensurate with metals when including the mixed arsenide nitride system. The impact of InGaN/GaN based LEDs for blue and green emitters has already been enormous (over a $250 million market in 1998) and the promise of nitride based lasers DVD applications is phenomenal. Within this context, in this paper, recent progress in microwave AlGaN/GaN HEMTs and AlGaN/InGaN blue lasers at UCSB on sapphire is presented.