Robust efficiency stability and excellent aging resistance broadband NIR all-inorganic LEDs based on Tellurium-doped germanate glasses for multifunctional applications

Abstract

Broadband near-infrared (NIR) spectroscopy based on glass-converted light-emitting diodes (gc-LEDs) has been of great interest to multifunctional applications ranging from night vision to chemical industry, stimulating the demand for exploring broadband NIR gc-LEDs with sufficient efficiency stability and aging resistance. Herein, an all-inorganic broadband NIR LEDs based on Te cluster-doped germanate glass is developed. Via adjustment of melting atmosphere and network topology of the glass matrix, active NIR Te cluster centers can be generated and stabilized in germanate glass and show a broad emission at 770 nm with a full width at half maximum (FWHM) of 260 nm under blue light excitation. By combining the Te-doped glass with a commercial blue LED chip, a high-performance NIR gc-LEDs is fabricated with an NIR output power of 14.21 mW@10.1% under a driving current of 400 mA. Particularly, the fabricated NIR-LED device exhibits high efficient stability with a relatively low-efficiency drop of 0.0023 %mA−1, and excellent aging resistance while retaining an electroluminescence intensity up 90 % of their initial value after aging for 480 h under harsh conditions, which is comparable to the commercial phosphors. Finally, its multifunctional application of gc-LEDs is also demonstrated.