The Preparation And Research Of Luminescent Porous Silicon Composite Materials

Etching single crystal p-type silicon by using chemical etching method, etching different resistivity of single crystal p-type silicon and single crystal n-type silicon by using electrochemical corrosion method of the single slot. First, to verify the chemical etching method can produce porous silicon, under ultraviolet light porous silicon may shine fluorescence. Under the same conditions, compared with electrochemical corrosion method, the preparing porous silicon layer of chemical corrosion is much thinner, and the fluorescence from porous silicon is easy to be weakened when exposed to air it oxidizes. Porous silicon that are made from different resistivity of silicon wafers get different pore size. The hole of porous silicon from low resistivity of silicon wafer is much small, and from high resistivity of silicon wafer is larger, but the interior and the surrounding of the hole from high resistivity of silicon wafer exist spongy fiber structure.Exploration porous silicon composite luminescent materials:this paper respectively in peeling off and not shedding of porous silicon, bear fluorescence enhancement materials in porous silicon with different methods. Fluorescent reinforced materials refers to materials that with the380-780nm light excitation can emit fluorescence. This paper adds I2, C60, plant pigment (chlorophyll and lutein, etc.). Measuring the fluorescence lifetime and fluorescence spectrum of porous silicon, we obtain the average fluorescent lifetime of porous silicon is57.25M-S and fluorescence wavelength is from550nm to850nm; With electrolysis potassium iodide, iodine is added on the surface of porous silicon and in the hole. The average fluorescence lifetime of porous silicon/h composite materials is38.12Ms. Transfer rate constant of porous silicon can is about33%, and this pass rate is very low, so the iodine is not suitable for fluorescent agent of porous silicon; Porous silicon soak in C60tetrachloride solution and natural dry in the fume hood. The average fluorescence lifetime of porous silicon/C6o composite materials is1.66ns. The transfer rate constant reaches99.99%. We are not sure whether all the energy is used to shine, but we can determine the C60is a kind of potential fluorescent agent; Under the condition of the green light, the high concentration of photosynthesis system ii (PSII) drop on the surface of the porous silicon, and natural dry in the dark. The average fluorescent lifetime of porous silicon/PSII composite materials is 514.66ps. The transfer rate is almost100%. In the same way we can determine the PSII can serve as a potential fluorescent agent. Compared the fluorescence spectra of three kinds of composites with the fluorescence spectra of porous silicon itself。Fresh preparation of porous silicon is easily oxidized in the air, and hole wall is easily torn due to ethanol evaporation. In order to improve the crushing performance of porous silicon, spray varnish on the porous silicon which is not peeling off or coat varnish respectively on the two sides of the porous silicon. The experiment proves that this kind of composite material has a far shatter resistant properties superior to porous silicon material itself. Coat with a layer of organic glass,1,2-dichloroethane solution on a thickness of1mm organic glass plate, and put porous silicon on above, then coat organic glass1,2-dichloroethane solution, at last put a thickness of1mm the organic glass on the above. We get three-ply board of porous silicon-based composite luminescent materials, the experiment proved that this kind of composite material has a far shatter resistant properties superior to porous silicon material itself.