We present a procedure for the preparation of physically realistic models of paracrystalline silicon based on a modification of the bond-switching method of Wooten, Winer, and Weaire. The models contain randomly oriented c-Si grains embedded in a disordered matrix. Our technique creates interfaces between the crystalline and disordered phases of Si with an extremely low concentration of coordin...

Hydrogenated amorphous silicon (a-Si:H) has been already considered for the objective of passive optical elements, like waveguides and ring resonators, within photonic integrated circuits at λ = 1.55 μm. However the study of its electro-optical properties is still at an early stage, therefore this semiconductor in practice is not considered for light modulation as yet. We demonstrated, for the ...

We present a micro-electro-mechanical system-based experimental technique to measure thermal conductivity of freestanding ultra-thin films of amorphous silicon nitride (Si3N4) as a function of mechanical strain. Using a combination of infrared thermal micrography and multi-physics simulation, we measured thermal conductivity of 50 nm thick silicon nitride films to observe it decrease from 2.7 W...

Two types of hot-pressed silicon nitride, one having an amorphous grain-boundary phase (6 wt% yttria, 3 wt% alumina) and the other having a predominantly crystalline grain-boundary phase (8 wt% yttria, 1 wt% alumina), were tested on a split Hopkinson pressure bar with a momentum trap, such that, in each test, the sample was subjected to a single predefined stress pulse and then recovered withou...

Large-scale molecular dynamics simulations of nanoindentation on a (100) oriented silicon surface were performed to investigate the mechanical behavior and phase transformation of single crystalline silicon. The direct crystalline-to-amorphous transformation is observed during the nanoindentation with a spherical indenter as long as the applied indentation strain or load is large enough. This a...

Mixed-phase hydrogenated silicon oxide (SiOx:H) is applied to thin-film hydrogenated amorphous silicon germanium (a-SiGe:H) solar cells serving as both p-doped and n-doped layers. The bandgap of p-SiOx:H is adjusted to achieve a highly-transparent window layer while also providing a strong electric field. Bandgap grading of n-SiOx:H is designed to obtain a smooth transition of the energy band e...

In this work, thermodynamic phenomena in crystalline silicon irradiated by an ultrafast laser pulse were studied using the method of molecular dynamics simulations. The Stillinger–Weber potential was used to model the crystalline silicon. The temperature development in silicon when heated by an ultrafast laser pulse was tracked. Melting and resolidification processes and the resulting structura...

We report the bulk synthesis of hydrogenated, amorphous SixNy and SixOy nanowires using pools of molten gallium as the solvent medium and microwave plasma consisting of silane in nitrogen and silane in oxygen respectively. High densities of multiple nanowires nucleated and grew from molten gallium pools. The resulting nanowires were tens of nanometers in diameter and tens of microns long. Elect...

Powder formation in silane plasmas has been considered as a technology drawback because it might lead to the formation of macroscopic defects in the deposited layers. Here we summarize our recent efforts in controlling the formation of powder precursors, in particular, nanocrystalline silicon particles, aiming at their incorporation in the films. Indeed, the incorporation of clusters and crysta...