am5b12542_si_001.pdf (627 kB)
Structure-Dependent Spin Polarization in Polymorphic CdS:Y Semiconductor Nanocrystals
journal contribution
posted on 2016-02-23, 00:00 authored by Pan Wang, Bingxin Xiao, Rui Zhao, Yanzhang Ma, Mingzhe ZhangSearching
for the polymorphic semiconductor nanocrystals would provide precise
and insightful structure-spin polarization correlations and meaningful
guidance for designing and synthesizing high spin-polarized spintronic
materials. Herein, the high spin polarization is achieved in polymorphic
CdS:Y semiconductor nanocrystals. The high-pressure polymorph of rock-salt
CdS:Y nanocrystals has been recovered at ambient conditions synthesized
by the wurtzite CdS:Y nanocrystals as starting material under 5.2
GPa and 300 °C conditions. The rock-salt CdS:Y polymorph displays
more robust room-temperature ferromagnetism than wurtzite sample,
which can reach the ferromagnetic level of conventional semiconductors
doped with magnetic transition-metal ions, mainly due to the significantly
enhanced spin configuration and defect states. Therefore, crystal
structure directly governs the spin configuration, which determines
the degree of spin polarization. This work can provide experimental
and theoretical methods for designing the high spin-polarized semiconductor
nanocrystals, which is important for applications in semiconductor
spintronics.