Photoluminescence spectra of C60 molecules embedded in porous Si

Abstract

The photoluminescence (PL) spectra of C60 molecules embedded in porous Si through both physical deposition and chemical coupling were measured. In addition to the PL peak of porous Si, a peak at 730 nm caused by perfect C60 molecules and other peaks at 620 and 630 nm caused by imperfect C60 molecules were observed. The peak at 620 nm measured in the sample with physically deposited C60 is induced by C60 adsorbed on the Si atoms of the pore wall, while the peak at 630 nm measured in the sample with chemically coupled C60 molecules is caused by the coupled C60 molecules. At room temperature, the PL intensity of C60 embedded in the porous Si is obviously enhanced, and the transfer of carriers from porous Si grains into adjacent C60 is considered to be responsible for the PL enhancement.