An improved method of fitting point-by-point is proposed to determine the absorption coefficient from infrared(IR)transmittance. With no necessity of empirical correction factors, the absorption coefficient can be accurately determined for the films with thin thicknesses. Based on this method, the structural properties of the hydrogenated amorphous silicon oxide materials(a-SiOx:H) are investigated. The oxygen-concentration-dependent variation of the Si–O–Si and the Si–H related modes in a-SiOx:H materials is discussed in detail.
In this article, a new type of superimposing morphology comprised of a periodic nanostructure and a random structure is proposed for the first time to enhance the light scattering in silicon-based thin film solar cells. According to the framework of the Reyleigh–Sommerfeld diffraction algorithm and the experimental results of random morphologies, we analyze the light-scattering properties of four superimposing morphologies and compare them with the individual morphologies in detail. The results indicate that the superimposing morphology can offer a better light trapping capacity, owing to the coexistence of the random scattering mechanism and the periodic scattering mechanism. Its scattering property will be dominated by the individual nanostructures whose geometrical features play the leading role.
Both one-dimensional nanostructures and porous nanostructures are benefit to the sensing enhancement of semiconducting functional materials.The present paper shows an effective route to combining the advantages of these two nanostructures for a novel type of ZnO nanomaterials.Basically,a pore-forming material is employed in an electrospinning method,and the products are characterized by X-ray powder diffraction(XRD),energy dispersive X-ray spectroscopy(EDX),and transmission electron microscopy(TEM).The obtained materials are loose ZnO nanofibers,which own both porous and one-dimensional nanostructures.Micro-sensors are fabricated by sputtering and etching techniques,and the as-prepared nanofibers are used as the functional materials in them.The sensors show improved sensing properties both in sensitivity and response-speeds.The sensitivity is enhanced from 4 to 8 and the response time is shortened from 14 to 10 s when the sensors are exposed to 100 μL/L ethanol at 260℃.Similar results are also observed in acetone and H2 sensing tests.These enhancements are based on the one-dimensional and porous nanostructures of the nanofibers.
