TITLE: Optical Spectroscopy of Porous Silicon: Implications towards a Chemical Sensor

SPEAKER:

TIME: Thursday Oct. 21, 1999 at 4 PM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

The efficient light emission mechanism of porous silicon is not well understood. Most models lean towards the presence of energy levels which result from quantum confinement of electrons within the porous structure. Our optical spectroscopy and photocurrent results indicate that the quantum confinement model is unlikely. Rather, continuous wave and time-resolved photoluminescence and Raman spectroscopy experiments yield results that point towards a complicated energy transfer system amongst the surface molecules. The details of the experiments and a preliminary model will be discussed in this seminar along with the suggestion that porous silicon appears to be a good candidate for a sensitive chemical sensor.