WIDE BAND-GAP SEMICONDUCTOR LIGHT EMITTERS

摘要

TYPE-II semiconductor heterojunction light emitting devices formed on a substrate (10) are described wherein a graded injection layer (18) is used to accelerate electrons over the electron barrier formed by the junction. Further, wide band gap semiconductor LEDs and lasers are proposed formed of II-VI materials which emit light in the blue and green wavelengths. Particularly, a system composed of n-CdSe:A1/MgxCd1-xSe/MgyZn1-yTe/p-ZnTe are described where the value of y determines the wavelength of the emitted light in the green or blue region and x varies across the graded injection layer for raising the energy levels of excited electrons.