TY - JOUR

T1 - Crossover in the conduction-band minimum of Ge quantum dots

AU - Reboredo, F.

AU - Zunger, Alex

PY - 2000

Y1 - 2000

N2 - Screened-pseudopotential calculations of large (Formula presented) atoms) surface-passivated Ge quantum dots show that below a critical dot diameter that depends on the passivant, the character of the lowest conduction state changes from an L-derived to an X-derived state. Thus, in this size regime, Ge dots are Si-like. This explains the absence, in a pseudopotential description, of a crossing between the band gaps of Si and Ge dots as a function of size, predicted earlier in single-valley effective-mass calculations. The predicted (Formula presented) crossing suggests that small Ge dots will have an X-like, red shift of the band gap with applied pressure, as opposed to an L-like blue shift of large dots.

AB - Screened-pseudopotential calculations of large (Formula presented) atoms) surface-passivated Ge quantum dots show that below a critical dot diameter that depends on the passivant, the character of the lowest conduction state changes from an L-derived to an X-derived state. Thus, in this size regime, Ge dots are Si-like. This explains the absence, in a pseudopotential description, of a crossing between the band gaps of Si and Ge dots as a function of size, predicted earlier in single-valley effective-mass calculations. The predicted (Formula presented) crossing suggests that small Ge dots will have an X-like, red shift of the band gap with applied pressure, as opposed to an L-like blue shift of large dots.

UR - http://www.scopus.com/inward/record.url?scp=0000008566&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.62.R2275

DO - 10.1103/PhysRevB.62.R2275

M3 - Article

AN - SCOPUS:0000008566

SN - 1098-0121

VL - 62

SP - R2275-R2278

JO - Physical Review B - Condensed Matter and Materials Physics

JF - Physical Review B - Condensed Matter and Materials Physics

IS - 4

ER -