Rare-earth implanted Si-based light emitters and their use for smart biosensor applications

We will review our recent progress in the development of Si-based light emitters consisting of a MOS structure with a rare-earth implanted SiO2 layer. Depending on the implanted element the devices exhibit strong electroluminescence in the UV and the visible spectral region. In order to improve the stability of the devices, both LOCOS (local oxidation of Si) processing and additional protection layers made of SiON were applied to the devices. The advantages and the shortcomings of these light emitters regarding their efficiency, lifetime, electrical excitation conditions and miniaturization potential are compared with the needs of smart photonic and biosensor applications. A special approach for utilizing the light emitters for the detection of organic pollutants in fluid media by fluorescence analysis is discussed in more detail. In this approach the light emitter is directly placed beneath the dye-labeled sample exciting the dye whose light emission can be recorded by a suitable external detector.