Picosecond carrier dynamics induced by coupling of wavefunctions in a Si-nanodisk array fabricated by neutral beam etching using bio-nano-templates
1 Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo, 060-0814, Japan
2 Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
3 Japan Science and Technology Agency, CREST, 5 Sanbancho, Chiyoda, Tokyo, 102-0075, Japan
Nanoscale Research Letters 2012, 7:587 doi:10.1186/1556-276X-7-587Published: 24 October 2012
The picosecond carrier dynamics in a closely packed Si-nanodisk (Si-ND) array with ultrathin potential barrier fabricated by neutral beam etching using bio-nano-templates was investigated by time-resolved photoluminescence (PL). The PL decay curves were analyzed as a function of photon energy by the global fitting method. We show three spectral components with different decay times, where the systematic energy differences of the spectral peaks are clarified: 2.03 eV for the fastest decaying component with a decay time τ = 40 ps, 2.02 eV for τ = 300 ps, and 2.00 eV for τ = 1.6 ns. These energy separations ranging from 10 to 30 meV among the emissive states can be attributed to the coupling of wavefunctions of carriers between neighboring NDs.