Work

Intense Visible and Near-Infrared Upconversion Photoluminescence in Colloidal LiYF 4 :Er 3+ Nanocrystals under Excitation at 1490 nm

Year: 2011

Type: article

Abstract: We report intense upconversion photoluminescence (PL) in colloidal LiYF(4):Er(3+) nanocrystals under excitation with telecom-wavelength at 1490 nm. The intensities of two- and three-photon anti-Stokes upconversion PL bands are higher than or comparable to that of the Stokes emission under excitation with low power density in the range 5-120 W/cm(2). The quantum yield of the upconversion PL was measured to be as high as ∼1.2 ± 0.1%, which is almost 4 times higher than the highest upconversion PL quantum yield reported to date for lanthanide-doped nanocrystals in 100 nm sized hexagonal NaYF(4):Yb(3+)20%, Er(3+)2% using excitation at ∼980 nm. A power dependence study revealed that the intensities of all PL bands have linear dependence on the excitation power density, which was explained by saturation effects in the intermediate energy states.

Source: ACS Nano

DOI: 10.1021/nn201083j

Authors: Guanying Chen, Tymish Y. Ohulchanskyy, Aliaksandr Kachynski, Hans Ågren, Paras N. Prasad

Institutions: University at Buffalo, State University of New York, KTH Royal Institute of Technology

Language: English

Topic: Luminescence Properties of Advanced Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: National Cancer Institute

Awards: Novel Cancer Nanotechnology Platforms for Photodynamic Therapy and Imaging, Application of Nanotechnology in Photodynamic Therapy