抄録
We report on the growth and optical properties of quaternary InAlGaN for the application of 250-350-nm-band bright ultraviolet (UV) light-emitting diodes (LEDs) or laser diodes (LDs). We demonstrated that the 300-nm-band UV emission is considerably enhanced by the In-segregation effect upon the introduction of 1-5% of In into AlGaN. We fabricated In_<x1>AlylGa_<1-x1-y1>N/In_<x2>Al_<y2> Ga_<1-x2-y2>N multi-quantum wells (MQWs) with various compositions, and obtained intense room-temperature emission in the wavelength range of 290-390 nm. The emission from the InAlGaN-based MQWs was as intense as the blue emission from InGaN-based QWs. We also fabricated UV-LEDs using a quaternary InAlGaN active region and achieved high-intensity 330 nm emission under RT CW operation. The UV intensity from quaternary InAlGaN-LED was more than one order of magnitude larger than that of AlGaN or GaN based LEDs.
