Broadband near infrared emission in Cr3+,Yb3+, Li+ tri-doped In2TeO6

Cr3+ near infrared (NIR) emission is witnessed in tellurite compound for the first time. Broadband emission that peaks at 840nm and has 157 nm of full width at half maxima (FWHM) appears in the Cr3+ doped In2TeO6 phosphor when excited at 455 nm. Further introduction of Li+ ions into the In2TeO6 can distort the octahedral environment of the doped Cr3+ ions, resulting in 4 times enhancement in luminescence intensity and a 1.75-fold enhancement in internal quantum efficiency (IQE). Moreover, the FWHM increases to 282nm in the In2TeO6: Cr3+,Li+,Yb3+ phosphor induced by the Cr3+ to Yb3+ energy transfer. LED device utilizing this NIR phosphor has been constructed. At 150 mA drive current, the optoelectrical efficiency is 11.189% and the NIR output power is 50.72 mW. The In2TeO6: Cr3+,Li+,Yb3+ phosphor exhibits enormous potential in NIR phosphor-converted LED (pc-LED).