Higher fullerene-coupled porous silicon systems with blue emission

Abstract Higher fullerenes (C 70 , C 76 , C 84 , C 94 ) were covalently coupled on porous Si (PS) to form fullerene-coupled PS systems. After stored in air for 3–13 months, a blue photoluminescence (PL) was observed in the range of 430–480 nm. PL excitation spectral examinations reveal that the photoexcited carriers are generated in the quantum confined nanocrystalline Si ( nc -Si ) cores, whereas radiative recombination occurs at the coupled nc -Si surface. Fourier-transform infrared absorption data disclose that the blue PL energy has a dependence on the oxygen content of nc -Si surface, indicating that the luminescent centers should be some oxygen-related defect states. Based on the annealing behavior of the blue PL peak in O 2 and N 2 , we attribute the luminescent center to a pair of an oxygen vacancy and an interstitial oxygen, which also forms a peroxy linkage with an lattice oxygen.