Photon avalanche upconversion and pump power studies in LaF 3:Er3+/Yb3+ phosphor

Abstract

Hexagonal LaF3:Er3+/Yb3+ phosphor material has been synthesized by chemical precipitation method to obtain high near-infrared to green upconversion (UC) efficiency. Its thermal, structural and fluorescence properties have been studied. UC emission bands have been observed up to 315 nm in UV region. The effect of input pump power on the intensities of various emission bands has been studied in detail and photon avalanche UC mechanism has been identified. On increasing the excitation power, some bands have shown saturation in intensity. Also, at higher pump intensities two new UC bands were observed and their origin has been discussed. The phosphor has also been tested for possible UC-based fingerprint detection. © 2011 Springer-Verlag.