Role of Quantum Confinement in Luminescence Efficiency of Group IV Nanostructures

Abstract

Experimental results obtained previously for the photoluminescence efficiency (PL${}_{eff}$) of Ge quantum dots (QDs) are theoretically studied. A $\log$-$\log$ plot of PL${}_{eff}$ versus QD diameter ($D$) resulted in an identical slope for each Ge QD sample only when $E_G\sim (D^2+D{)}^{-1}$. We identified that above $D\approx$ 6.2 nm: $E_G\sim D^{-1}$ due to a changing effective mass (EM), while below $D\approx$ 4.6 nm: $E_G\sim D^{-2}$ due to electron/ hole confinement. We propose that as the QD size is initially reduced, the EM is reduced, which increases the Bohr radius and interface scattering until eventually pure quantum confinement effects dominate at small $D$.

References in corpus (3)

• Single-particle states in spherical Si/SiO${}_2$ quantum dots
• Quantum Confinement in Nonadditive Space with a Spatially Dependent Effective Mass for Si and Ge Quantum Wells
• The 30-band k.p modeling of electron and hole states in silicon quantum wells

Cited by in corpus (5)

• A position-dependent mass harmonic oscillator and deformed space
• Generalized space and linear momentum operators in quantum mechanics
• Influence of interface potential on the effective mass in Ge nanostructures
• Supersymmetric quantum mechanics and coherent states for a deformed oscillator with position-dependent effective mass
• Two dimensional electron gas in a non-Euclidean space