Work

Temperature-induced nanostructural evolution of hydrogen-rich voids in amorphous silicon: a first-principles study

Year: 2019

Type: article

Abstract: The paper presents an ab initio study of temperature-induced nanostructural evolution of hydrogen-rich voids in amorphous silicon. By using large a-Si models, obtained from classical molecular-dynamics simulations, with a realistic void-volume density of 0.2%, the dynamics of Si and H atoms on the surface of the nanometer-size cavities were studied and their effects on the shape and size of the voids were examined using first-principles density-functional simulations. The results from ab initio calculations were compared with those obtained from using the modified Stillinger-Weber potential. The temperature-induced nanostructural evolution of the voids was examined by analyzing the three-dimensional distribution of Si and H atoms on/near void surfaces using the convex-hull approximation, and computing the radius of gyration of the corresponding convex hulls. A comparison of the results with those from the simulated values of the intensity in small-angle X-ray scattering of a-Si/a-Si:H in the Guinier approximation is also provided, along with a discussion on the dynamics of bonded and non-bonded hydrogen in the vicinity of voids.

Source: Nanoscale

DOI: 10.1039/c9nr08209c

Authors: Parthapratim Biswas, Durga Paudel, Raymond Atta-Fynn, Stephen R. Elliott

Institutions: University of Southern Mississippi, The University of Texas at Arlington, University of Cambridge

Language: English

Topic: Silicon and Solar Cell Technologies

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, University of Texas at Austin, Division of Materials Research

Awards: G2766040076, Collaborative Research: Joint utilization of experimental and theoretical information: a new paradigm for modeling complex materials, Collaborative Research : Joint utilization of experimental and theoretical information: a new paradigm for modeling complex materials, G7816486003