Internal photoluminescence and lifetime of light-emitting diodes on conductive ZnSe substrates

Abstract

We report on the molecular beam epitaxial growth of green (508 nm) and blue (489 nm) light-emitting diodes (LEDs) on conductive ZnSe substrates. The resistivity of the (001)-oriented ZnSe wafers was drastically reduced by a zinc extraction treatment to typical values of 1 × 10-1 Ω cm. The intensity of an additional orange band around 600 nm observed in electroluminescence depends strongly on the wavelength of the multi-quantum-well emission. This can be explained by absorption and effective re-emission in the substrate material named internal photoluminescence and was confirmed by transmission and photoluminescence experiments with the bare substrates. The LEDs with lifetimes up to 100 hours proofed to be surprisingly stable compared to the structures on undoped ZnSe substrates grown before. © 1997 American Institute of Physics.