Study Of The Low-dimensional Structures On The SiGe Alloys And The Photoluminescence

In this paper, a variety of low-dimensional quantum structures are formed on the SiGe alloy by the strong laser irradiation and the electrochemical etching with the weak laser irradiation assisted. This paper centers on two aspects:1,we investigate the formation of low-dimensional quantum structures with different experimental conditions;2,we study the photoluminescence of the low-dimensional quantum structures and try to analyze the mechanism of the photoluminescence.The relationship of the experimental conditions and low-dimensional quantum structures is studied with the SEM technology.(1) Germanium quantum dots are formed on the silicon-germanium sample by laser irradiation with laser defocusing in the silicon germanium alloy film. Hole structure is formed on the silicon-germanium sample by laser irradiation with the laser focusing on the silicon germanium thin films and the piece structure is formed at the inside of the hole.(2) A shorter time of irradiation (beam spot diameter: 700 um) on the strained Si_1-xGe_x film can form some dots and lines structures. A longer irradiation (beam spot diameter: 300um) can dig up the Si_1-xGe_x film along certain direction to form some strap pieces. Under anodizing and irradiating for 30 min, the Si_1-xGe_x layer is almost dug out and a deeper porous region forms on the substrate.The PL spectra of the samples under the 514 nm excitation were measured by using RENISHAW Raman Systems.A new model of three-level system associated with the crystal-oxide interface state has been proposed for interpreting the PL...