Tunability Limit of Photoluminescence in Colloidal Silicon Nanocrystals
Xiaoming Wen, Pengfei Zhang, Trevor A Smith, Rebecca J Anthony, Uwe R Kortshagen, Pyng Yu, Yu Feng, Santosh Shrestha, Gavin Coniber, Shujuan Huang
SCIENTIFIC REPORTS | NATURE PUBLISHING GROUP | Published : 2015
Luminescent silicon nanocrystals (Si NCs) have attracted tremendous research interest. Their size dependent photoluminescence (PL) shows great promise in various optoelectronic and biomedical applications and devices. However, it remains unclear why the exciton emission is limited to energy below 2.1 eV, no matter how small the nanocrystal is. Here we interpret a nanosecond transient yellow emission band at 590 nm (2.1 eV) as a critical limit of the wavelength tunability in colloidal silicon nanocrystals. In the "large size" regime (d > ~3 nm), quantum confinement dominantly determines the PL wavelength and thus the PL peak blue shifts upon decreasing the Si NC size. In the "small size" regi..View full abstract
Awarded by UMN MRSEC Program of the National Science Foundation
This Program has been supported by the Australian Government through the Australian Renewable Energy Agency (ARENA). U.K. and R.J.A. were supported by the UMN MRSEC Program of the National Science Foundation under Award Numbers DMR-0819885 and DMR-1420013.