Hole-net Structure And Photoluminescence On Silicon By Irradiation Of Laser

A kind of hole-net structure can be formed on silicon sample by irradiation with pulse laser of power 30W,wavelength 1064nm,repeat frequency 800HZ and pulse width 8ns. The photoluminescence (PL) emission is enhanced in the hole-net structure. The PL peak center is about 706nm. The optimum conditions are obtained in preparing (irradiation time and laser power). We have found that the PL peak center do not alter with changing sizes of hole-net structure. Pinning effect of PL emission is not interpreted by quantum confinement alone. Under the optimum conditions in preparing process, the sample with an enhanced PL emission and more stable low-dimensional structures can be obtained by 9s irradiationA series of experiments have been designed to detect the affection of the oxidation on the hole-net structure of silicon to PL emission. In the preparing and detecting process, the sample irradiated was immersed in HF,ethanol, and pure water, respectively. it is found that there is no PL emission almost on the earlier oxygen-free samples in HF and ethanol; It is found that there is weak PL emission on samples in pure water because pure water under laser irradiation releases oxygen. It is confirmed that the oxygen plays an important role in PL emission of sample. The enhancing effect of the PL emission is not interpreted by the model of the quantum confinement and luminescence center. So a model for explaining the effect was proposed in which the trap states of the interface between SiO₂ and low-dimensional nanocrystal play an important role. The plasma wave model is used to explain the mechanism forming hole-net structure.