Broadband near-infrared emission of K3ScF6:Cr3+ phosphors for night vision imaging system sources

Abstract

• K 3 ScF 6 :Cr 3+ can be excited by blue light, leading to a broadband NIR emission. • K 3 ScF 6 :Cr 3+ retain 87.3% of their initial emission intensity at 150 °C. • The fabricated NIR-LED based on K 3 ScF 6 :Cr 3+ has good photoelectric efficiency. • NIR-LED based on K 3 ScF 6 :Cr 3+ can be applied in night vision imaging systems. Broadband near-infrared light (NIR) near 800 nm has broad application prospects in food detection and night vision monitoring. Compared with NIR chips, NIR phosphors have distinct advantages, including low cost, a mature synthesis process, and tunable combination. However, at present, oxide NIR phosphors have some disadvantages, such as a narrow full width at half maximum (FWHM), poor thermal stability, and low photoelectric efficiency. Herein, K 3 ScF 6 :Cr 3+ NIR phosphors with a cubic structure were synthesized using the hydrothermal method. These phosphors can be effectively excited by blue light (430 nm) and red light (630 nm), leading to a broadband Cr 3+ emission from 650 nm to 950 nm with a large FWHM of 430 nm. They also exhibit excellent thermal stability and retain 87.3% of their initial intensity at 150 °C. Under a driving current of 100 mA, their photoelectric efficiency can reach 9.315% of that of fabricated NIR light-emitting diodes (NIR-LED). An NIR-LED device based on this phosphor can thus be implemented in night vision imaging systems.