Surface Modification And Spectral Analysis Of Silicon Quantum Dots

Due to its low cost and low toxicity, Silicon materials prices are widely used in display、solar cells and other fields. Silicon quantum dots have good optically properties, it makes the study for the optical properties of silicon quantum dots have important value. This paper will research the preparation of silicon quantum dots as well as the influence of surface modification on its optical properties. The main points can be listed as follows:(1) In this work, electrochemical method has been used to synthesize hydrogen-terminated Si QDS,the results show that well-size-distributed silicon quantum dots were between 3-4 nm, it also has obvious fluorescence emission in 469 nm, But its fluorescence intensity was not stable,it would be decay with the storage time became longer.(2) Based on the surface oxidation of Silicon quantum dots,We prepared silicon quantum dots of SiO2 modified, With the increase of oxidation time, We found that the size of silicon quantum dots became smaller. Due to the size-dependent quantum confinement, its fluorescence emission peak can be blue shift to 373 nm.(3)We prepared silicon quantum dots of the carboxyl modified and we analyzed the change of the luminescent properties. Ftir results proved that the carboxyl successfully modified on the surface of silicon quantum dots and the photoluminescence peak can be blue shift after surface modification.