Electroluminescence of Si Quantum Dots in MOS Structures

摘要

We have studied the structural, electrical and optical properties of MOS devices, where the dielectric layer consists of a substoichiometric SiO_x (x < 2) thin film deposited by plasma enhanced chemical vapor deposition. After deposition the SiO_x samples were annealed at 1250℃ for 1 h; the thermal treatment induces the separation of the Si and SiO_2 phases with the formation of Si nanocrystals embedded in the insulating matrix. We observed at room temperature a quite intense electroluminescence signal that is attributed to emission from silicon nanocrystals. The effects of the Si concentration in the SiO_x layer on the electrical and optical properties of these devices are reported and discussed.