Method for preparing silicon-nanoparticle-containing silicon nitride thin films

Abstract

The invention discloses a method for preparing silicon-nanoparticle-containing silicon nitride thin films, which comprises the following steps: (1) cleaning a p-type monocrystalline silicon substrate; (2) preparing silicon-enriched non-stoichiometric silicon nitride thin films on substrates by a plasma enhanced chemical vapor deposition technique; and (3) placing the prepared silicon nitride thin films in a quartz furnace, and annealing at a high temperature of 750 to 800 DEG C by using nitrogen as a protective gas, namely directing heating a quartz tube annealing furnace to 750 to 850 DEG C, keeping the temperature for 8 to 12 minutes, and cooling to room temperature through the self-radiation of the quartz tube annealing furnace without any addition cooling measures. And after the non-stoichiometric silicon nitride thin films undergo high-temperature annealing, silicon nanoparticles are embedded in silicon nitride thin films through a phase separation process. The silicon nanopartiles embedded in the silicon nitride thin films are mainly characterized by uniform silicon nanoparticle size, high order, strong quantum confinement effect and simple preparation process.

Description

technical field [0001] The invention belongs to the technical field of manufacturing silicon nanomaterials, and in particular relates to a method for preparing a silicon nitride film containing silicon nanoparticles technical background [0002] Silicon has been used as a semiconductor material for more than 40 years in integrated circuits and solar cell applications. Due to the clean and non-polluting characteristics of silicon solar cells and the possibility of solving the world's energy crisis, silicon solar cells have been extensively studied in terms of solar cells and preparation technology. At present, the maximum photoelectric conversion efficiency of silicon-based solar cells in laboratory research has reached 24.7%, gradually approaching its theoretical upper limit of 30%. Studies have shown that if the size of silicon nanoparticles can be reduced to be comparable to its excitonic Bohr radius, silicon nanoparticles can generate multiple electron-hole pairs for eac...

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Problems solved by technology

[0005] (1) Although silicon carbide has the lowest potential barrier among the three substrates, the attenuation length of the electron wave function is the largest, which is conducive to the tunneling and injection of carriers, and the carriers have a higher Hall mobility, which is an ideal The parent matrix material, but due to the difference in the lattice spacing of Si-C in Si-Si and silicon carbide, the difference in lattice spacing between Si-O and Si-N in silicon oxide and nitride is smaller, and the difference in lattice spacing between SiC and Si It is an equivalent electronic structure material, which makes it difficult for silicon nanoparticles to form in a silicon carbide matrix