Characteristics of ultraviolet laser diodes composed of quaternary AlxInyGa(1-x-y)N

Ultraviolet (UV) laser diodes (LDs) whose active layers were composed of qu aternary AlxInyGa(1-x-y)N were grown on epitaxially laterally overgrown GaN substrates by a metalorganic chemical vapor deposition method. We investig ated the Al and In mole fractions dependence of LD characteristics in the U V region. The emission wavelength of the LDs whose active layers consisted of Al0.03In0.02Ga0.95N single quantum well (SQW) was 366.4 nm under pulsed current injection at room temperature. The lasing wavelength was the shorte st ever reported for III-V nitride-based LDs. The Al0.03In0.03Ga0.94N SQW U V LDs were demonstrated under 25 degreesC continuous-wave (cw) operation. T he threshold current density and voltage of these LDs were 3.5 kA/cm(2) and 4.8 V, respectively. The estimated lifetime was approximately 500 h under 25 degreesC ew operation at an output power of 2 mW.