Geometry-dependent band shift and dielectric modification of nanoporous Si nanowires

Abstract

In order to obtain a detailed understanding of the modulation of electronic properties in nanoporous Si (np-Si) nanowires with containing ordered, nanometer-sized cylindrical pores, we propose a theoretical method to clarify the band shift and associated with the dielectric modification determined by the geometrical parameters, including nanowire diameter, pore size, pore spacing and porosity, in terms of size-dependent surface energy and atomic-bond-relaxation correlation mechanism. Our results reveal that the self-equilibrium strain induced by the atoms located at inner and outer surfaces with high ratio of under-coordinated atoms as well as elastic interaction among pores in np-Si nanowires play the dominant role in the bandgap shift and dielectric depression. The tunable electronic properties of np-Si nanowires with negative curvature make them attractive for nanoelectronic and optoelectronic devices.

Thickness-dependent photoelectric properties of MoS2/Si heterostructure solar cells

“…According to ABR mechanism, the abrupt termination of bonding network can leave a high dangling bond and coordination deficiency in the end parts 26,27 . Thus, the system will be in a self-equilibrium state and the strain will be occurrence, which makes some relevant quantities such as electronic density and binding energy distinctive from their corresponding bulk 20,28 . Notably, the bond strain can be expressed as: , where d * and d 0 , respectively, denote the average bond length and that of the bulk.…”

The template-assisted electrodeposition of platinum nanowires for catalytic applicati

“…It is generally accepted that the diameter of nanowires plays a fundamental role in their functionality. As the diameter of nanowires decreases, their surface-to-volume ratio increases and consequently, the variation of the surface energy significantly influences the surface state and the related physical and chemical properties [16]. Although many studies have investigated the template-based electrodeposition of Pt NWs, very few researchers have examined distinct morphological and structural properties of Pt NWs fabricated on templates with different pore diameters.…”