A high-density array of size-controlled silicon nanodots in a silicon oxide nanowire by electron-stimulated oxygen expulsion.
Methods of producing Si nanodots embedded in films of silicon oxide and silicon nitride abound, but fabrication of Si nanodots in a nanowire of these materials is very rare despite the fact that nanowire architecture enhances the charge collection and transport efficiencies for solar cells and field-effect transistors. We report a novel fabrication method for a high-density array of size-controlled sillicon nanodots from a silicon oxide nanowire using electron-beam irradiation. Our results demonstrate that a highly dense phase of Si nanodots with a narrow size distribution can be made from a silicon oxide nanowire with a core-shell structure of crystalline silicon-rich oxide (c-SRO)/amorphous silicon oxide (a-SiO(2)). This new nanomaterial shows the carrier transport characteristics of a semiconductor. The initially produced amorphous Si nanodots can be readily turned into crystalline Si (c-Si) nanodots by thermal annealing. Key characteristics of c-Si nanodots such as their size, number density, and rate of nucleation and growth are easily controlled by varying the electron radiation dose and annealing temperature. Nanodot formation is mechanistically initiated by electron trapping at the c-SRO core as well as at the core-shell interface, which leads to out-diffusion of the negatively charged oxygen through Coulomb repulsion, fostering the aggregation of Si atoms.
Analytical Engineering Center, Samsung Advanced Institute of Technology, PO Box 111, Suwon, Korea 440-600. gs8144.park@samsung.com
Gyeong-Su
GS
Park
Eun Kyung
EK
Lee
Jun Ho
JH
Lee
Juyeon
J
Park
Seong Keun
SK
Kim
Xiang Shu
XS
Li
Ju Cheol
JC
Park
Jae Gwan
JG
Chung
Woo Sung
WS
Jeon
Sung
S
Heo
Jae Hak
JH
Lee
Byoung Lyong
BL
Choi
Jong Min
JM
Kim