Giant Zeeman splitting in nucleation-controlled doped CdSe:Mn2+ quantum nanoribbons.
Doping of semiconductor nanocrystals by transition-metal ions has attracted tremendous attention owing to their nanoscale spintronic applications. Such doping is, however, difficult to achieve in low-dimensional strongly quantum confined nanostructures by conventional growth procedures. Here we demonstrate that the incorporation of manganese ions up to 10% into CdSe quantum nanoribbons can be readily achieved by a nucleation-controlled doping process. The cation-exchange reaction of (CdSe)(13) clusters with Mn(2+) ions governs the Mn(2+) incorporation during the nucleation stage. This highly efficient Mn(2+) doping of the CdSe quantum nanoribbons results in giant exciton Zeeman splitting with an effective g-factor of approximately 600, the largest value seen so far in diluted magnetic semiconductor nanocrystals. Furthermore, the sign of the s-d exchange is inverted to negative owing to the exceptionally strong quantum confinement in our nanoribbons. The nucleation-controlled doping strategy demonstrated here thus opens the possibility of doping various strongly quantum confined nanocrystals for diverse applications.
Yu
Jung Ho
JH
National Creative Research Initiative Center for Oxide Nanocrystalline Materials and School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Korea.
Liu
Xinyu
X
Kweon
Kyoung Eun
KE
Joo
Jin
J
Park
Jiwon
J
Ko
Kyung-Tae
KT
Lee
Dong Won
DW
Shen
Shaoping
S
Tivakornsasithorn
Kritsanu
K
Son
Jae Sung
JS
Park
Jae-Hoon
JH
Kim
Young-Woon
YW
Hwang
Gyeong S
GS
Dobrowolska
Margaret
M
Furdyna
Jacek K
JK
Hyeon
Taeghwan
T