Long-Wavelength Broadband Near-Infrared ZrTe<sub>3</sub>O<sub>8</sub>:Cr<sup>3+</sup>, Ti<sup>4+</sup> Phosphor of High Luminescence Quantum Yield and Excellent Thermal Stability
Linchong Wang, Siguo Xiao, Xiaoliang Yang
Abstract
Currently Cr 3+ ion-activated broadband near-infrared (NIR) phosphors for phosphor-converted light-emitting diodes (pc-LEDs) are receiving much attention. However, developing a high quantum yield (QY) and excellent luminescence thermal stability of Cr 3+ ion-activated phosphors with an emission peak exceeding 850 nm is still a great challenge. In the present work, ZrTe 3 O 8:Cr 3+ (ZTO:Cr 3+ ) phosphor has been prepared via a high-temperature solid-state reaction method, and its NIR emission wavelength ranges from 700 to 1200 nm with peak 889 nm and full width at half-maximum (fwhm) up to 195 nm under 455 nm light excitation. Partial substitution of Zr 4+ ions by Ti 4+ in the phosphor enhances the luminescence intensity by 1.65-fold. The optimized ZTO:Cr 3+, Ti 4+ phosphor exhibits an internal quantum efficiency (IQY) of 64.9% and the emission intensity remains at 73.82% of the room temperature (298 K) when the temperature is increased to 423 K. This indicates that the long-wavelength broadband NIR phosphor developed in the present work exhibits both excellent thermal stability of luminescence and high IQY, which is promising for night vision, nondestructive testing, and bioimaging applications.