Miniband formulation in Ge/Si quantum dot array

Abstract

Enhanced quantum confinement due to nonuniform composition in alloy quantumdots M Z Hossain, N V Medhekar, V B Shenoy et al.In this work, we estimate the coupling effect of miniband structure and density of states (DoS) resulting from different qunatum-dot physical parameters in a well-aligned Ge/Si quantum dot (QD) array fabricated by neutral beam etching technology. The density of QDs dominates the coupling effect and miniband's bandwidth, the radius of QDs affects the magnitude of energy levels and miniband bandwidth, and the thickness of QDs has a great impact on the magnitude of energy levels. Among the different shapes of Ge/Si QDs, discoid QDs exhibit the most band crossing and broadest bandwith under the same physical parameters.

Physical and electrical characteristics of Si/SiC quantum dot superlattice solar cells with passivation layer of aluminum oxide

“…Figures 5(c) and (d) exhibit the minimum transition energy and the effective bandgap versus h and zDot for the square and hexagonal (inset) QDSLs configurations. In comparison with those low states, the QDs with a thicker h introduce more continuous energy levels [33] and the minibands coupling occurs strongly for those high boundedstates [22]. Therefore, the effective bandgap reduces more significant than that of the minimum transition energy.…”

On the energy band of neutral-beam etched Si/Si0.7Ge0.3 nanopillars

“…1(d), are simulated. To consider the process variation, 38) the Si NPs in the unit cell with elliptical and conical shapes, as shown in Figs. 1(e) and 1(f), are also examined.…”