尺寸及表面氟化对多孔硅光电性能的影响

F4 plasma-passivation enhanced size dependence of the blue-shift in photo-emission and photo-absorption, E2p-level shift and band-gap expansion of porous silicon has been measured and analyzed numerically based on the recent “bond order-length-strength” (BOLS) correlation [C. Q. Sun, Phys. Rev. B69, 045105 (2004)]. Matching predictions to the measurements conducted before and after fluorination reveals that fluorination further enhances both the crystal binding intensity that determines the band gap and core level shift and the electron-phonon coupling that contributes to the energies of photo-emission and photo-absorption. This approach enables us to discriminate the effect of surface-bond contraction from the effect of surface-bond nature alteration on the unusual behavior of photons, phonons and electrons in nanosolid Si.