Advances in the development of graded injector visible light emitters

Novel visible light emitters with low turn-on voltages and efficient room temperature operation have been demonstrated in the n-CdSe/p-ZnTe heterojunction separated by a graded MgxCd1−xSe injecting region. The successful p-type doping of ZnTe up to 1 × 1020 cm-3 using a nitrogen plasma source has allowed using higher quality GaSb substrates and growing of p-ZnTe epilayers. Diodes with ideality factors of 1.8 are realized with turn-on voltages near that of the bandgap of ZnTe. This deviation from an ideality of 1 may be due to using too small a peak Mg concentration in the MgnCd1−xSe layer resulting in a barrier for electron injection and increasing recombination at the interface.