We demonstrate wavelength-tunable, air-stable and nontoxic phosphor materials based on silicon quantum dots (SiQDs). The phosphors, which are composed of micrometer-size silicon particles with attached SiQDs, are synthesized by an electrochemical etching method under ambient conditions. The photoluminescence (PL) peak wavelength can be controlled by the SiQD size due to quantum confinement effect, as well as the surface passivation chemistry of SiQDs. The red-emitting phosphors have PL quantum yield equal to 17%. The SiQD-phosphors can be embedded in polymers and efficiently excited by 405 nm light-emitting diodes for potential general lighting applications.
© 2012 Optical Society of America
Original Manuscript: September 11, 2012
Revised Manuscript: October 15, 2012
Manuscript Accepted: October 16, 2012
Published: November 14, 2012
Chang-Ching Tu, Ji-Hao Hoo, Karl F. Böhringer, Lih Y. Lin, and Guozhong Cao, "Surface passivation dependent photoluminescence from silicon quantum dot phosphors," Opt. Lett. 37, 4771-4773 (2012)