New concept for organic LEDs: non-radiative electronic energy transfer from semiconductor quantum well to organic overlayer

The resonant electronic energy transfer from an excited semiconductor quantum well to a nearby strongly absorbing organic medium may occur on time scales of several tens of picoseconds for II-VI semiconductors and of several hundreds picoseconds for III-V semiconductors, which is in both cases significantly less than the semiconductor excitation life-time in the absence of such a transfer. Thus, a large fraction of the semiconductor excitation energy can be transfered to the organic medium. Due to energy transfer the non-radiative processes in the semiconductor quantum well. with characteristic times larger than that of the energy transfer, will be suppressed. The advantage of the hybrid structures would be also the combination of comparatively good transport properties of semiconductors (allowing for electrical pumping) and good light-emitting properties of organic substances thigh quantum yield, colour tuning). Such a favorable combination may be exploited in constructing new type of LEDs. (C) 2001 Elsevier Science B.V. All rights reserved.