Study of single silicon quantum dots' band gap and single-electron charging energies by room temperature scanning tunneling microscopy.
Scanning tunneling spectroscopy in the shell-filling regime was carried out at room temperature to investigate the size dependence of the band gap and single-electron charging energy of single Si quantum dots (QDs). The results are compared with model calculation. A 12-fold multiple staircase structure was observed for a QD of about 4.3 nm diameter, reflecting the degeneracy of the first energy level, as expected from theoretical calculations. The systematic broadening of the tunneling spectroscopy peaks with decreasing dot diameter is attributed to the reduced barrier height for smaller dot sizes and to the splitting of the first energy level.
Zaknoon
Bashir
B
Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
Bahir
Gad
G
Saguy
Cecile
C
Edrei
Rachel
R
Hoffman
Alon
A
Rao
Rajesh A
RA
Muralidhar
Ramachandran
R
Chang
Ko-Min
KM
D004579:Electron Transport; D004583:Electrons; D008422:Materials Testing; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D010316:Particle Size; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*; D013696:Temperature
D012825:Silicon