Broadening and enhancing emission of Cr^(3+) simultaneously by co-doping Yb^(3+) in Ga1.4ln0.6SnO5

Cr^(3+)doped broadband near-infrared(NIR) emitting phosphors are currently the focus of research.Researchers have developed a variety of strategies to achieve broad and strong NIR emission,However,it is a conundrum to simultaneously broaden and enhance the emission of Cr^(3+)with a single strategy,In this work,we solved this problem by co-doping Yb^(3+).Under 452 nm excitation,Ga_(1.4)In_(0.6)SnO_(5)(GISO):0.01Cr^(3+)shows ultrabroadband NIR emission covering 650-1300 nm with a peak of 884 nm,The full width half maximum(FWHM) of the emission is 215 nm and the internal quantum yield(IQY) is 25%.This indicates that the double sites occupation strategy is favorable to achieve ultra-broadband NIR emission.The co-doping of Yb^(3+)can effectively broaden and enhance the emission of Cr^(3+).The FWHM for GISO:0.01Cr^(3+),0.002Yb^(3+)extends to 245 nm,and the IQY increases to 28%.Further increasing the concentration of Yb^(3+)to 0.005,the IQY is lifted to 32%.Finally,a phosphor-co nverted light emitting diode(pc-LED) was prepared by integrating the GISO:0.01Cr^(3+),0.002Yb^(3+)with a blue light chip.Under the current drive of 40 mA,the maximum output power of pc-LED is 4.54 mW,and the photoelectric conversion efficiency is 4.12%.These results indicate that Yb^(3+)ions can simultaneously broaden the emission band and improve the emission efficiency.This work provides an effective strategy for the design of efficient broadband NIR phosphors in the future.

Ultra-broadband near infrared phosphor with wide spectral range and long peak wavelength achieved by double-site occupation

The miniaturization and intelligence of near infrared(NIR)devices urgently require an excellent broadband NIR phosphor.However,emission spectra of most NIR phosphors cover less than 1200 nm with a full width at half maximum(FWHM)less than 200 nm and a peak wavelength less than 900 nm.Here,we successfully developed ultra-broadband NIR phosphors ScNbO_(4):Cr^(3+)which can overcome the above shortcomings based on a double-site occupancy strategy.The phosphors achieve ultra-broadband NIR emission from 800 to 1400 nm with a peak wavelength at 980 nm.Its FWHM is up to 217 nm.The valence state of Cr ions in phosphors was analyzed.The double-site occupancy of Cr^(3+)ions in the host and the relationship between host structure and optical properties are discussed in detail.NIR light transmission experiments show that phosphors have potential application value in non-destructive analysis.This work develops an excellent NIR luminescent material and provides an efficient method to obtain ultra-broadband NIR phosphors with longer peak wavelength.