INTERNAL PHOTOLUMINESCENCE AND LIFETIME OF LIGHT-EMITTING-DIODES ON CONDUCTIVE ZNSE SUBSTRATES

We report on the molecular beam epitaxial growth of green (508 nm) and blue (489 nm) light-emitting diodes (LEDs) on conductive ZnSe substra tes. The resistivity of the (001)-oriented ZnSe wafers was drastically reduced by a zinc extraction treatment to typical values of 1x10(-1) Omega cm. The intensity of an additional orange band around 600 nm obs erved 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 photolu minescence and was confirmed by transmission and photoluminescence exp eriments with the bare substrates. The LEDs with lifetimes up to 100 h ours proofed to be surprisingly stable compared to the structures on u ndoped ZnSe substrates grown before. (C) 1997 American Institute of Ph ysics. [S0021-8979(97)02621-2].