Amorphous silicon

About: Amorphous silicon is a research topic. Over the lifetime, 26777 publications have been published within this topic receiving 423234 citations.

TEM investigation on the structure of amorphous silicon monoxide

Abstract: Commercially available powder samples of silicon monoxide have been investigated by methods of transmission electron microscopy: electron scattering, electron energy-loss spectroscopy (EELS) and electron spectroscopic imaging (ESI). Pair distribution functions (PDFs) as well as EEL spectra can be shown to be a composition of the PDF and EEL spectra of elemental silicon and amorphous SiO2. The distribution of the elements silicon and oxygen calculated from ESI images proof the silicon monoxide to be inhomogeneous, i.e. it consists of amorphous silicon and amorphous SiO2. The phase separated regions measure ≈3–4 nm. One maximum in the PDF at 2.95 A does not stem from either a-Si or a-SiO2, and it is assigned to atomic configurations at the interphase boundary layer between Si and SiO2. The portion of the interphase domain in the total composite material is estimated to be between 20% and 25%.

Mixed-phase p-type silicon oxide containing silicon nanocrystals and its role in thin-film silicon solar cells

Abstract: Lower absorption, lower refractive index, and tunable resistance are three advantages of amorphous silicon oxide containing nanocrystalline silicon grains (nc-SiOx) compared to microcrystalline silicon (μc-Si), when used as a p-type layer in μc-Si thin-film solar cells. We show that p-nc-SiOx with its particular nanostructure increases μc-Si cell efficiency by reducing reflection and parasitic absorption losses depending on the roughness of the front electrode. Furthermore, we demonstrate that the p-nc-SiOx reduces the detrimental effects of the roughness on the electrical characteristics, and significantly increases μc-Si and Micromorph cell efficiency on substrates until now considered too rough for thin-film silicon solar cells.

Crystallization Behavior of Amorphous Silicon Carbonitride Ceramics Derived from Organometallic Precursors

Abstract: The crystallization behavior of organometallic-precursor-derived amorphous Si-C-N ceramics was investigated under N2 atmosphere using X-ray diffractometry (XRD), transmission electron microscopy (TEM), and solid-state 29Si nuclear magnetic resonance (NMR) spectroscopy. Amorphous Si-C-N ceramics with a C/Si atomic ratio in the range of 0.34–1.13 were prepared using polycarbosilane-polysilazane blends, single-source polysilazanes, and single-source polysilylcarbodiimides. The XRD study indicated that the crystallization temperature of Si3N4 increased consistently with the C/Si atomic ratio and reached 1500°C at C/Si atomic ratios ranging from 0.53 to 1.13. This temperature was 300°C higher than that of the carbon-free amorphous Si-N material. In contrast, the SiC crystallization temperature showed no clear relation with the C/Si atomic ratio. The TEM and NMR analyses revealed that the crystallization of amorphous Si-C-N was governed by carbon content, chemical homogeneity, and molecular structure of the amorphous Si-C-N network.