Broad-Band Near-Infrared Emission with High External Quantum Efficiency from Molybdenum-Doped Vacancy-Ordered Double Perovskites for Spectroscopic Analysis
Guodong Zhang, Liang Li, Y. J. Mao, Peipei Dang, Yaning Zhao, Hao Suo, Zhijun Wang, Panlai Li, Ziyong Cheng, Hongzhou Lian, Jun Lin
Abstract
Broad-band near-infrared (NIR) luminescent materials are crucially important components of NIR light-emitting devices (LEDs) and have garnered significant attention for their wide-ranging applications in spectroscopy analysis. Here, we present vacancy-ordered double perovskite Cs 2 HfCl 6 single crystals, which achieve efficient broad-band NIR emission through Mo 4+ ion doping. The optimized sample has an internal quantum efficiency of 85.1% and an ultrahigh external quantum efficiency of 68.3%. Experimental characterizations and theoretical calculations reveal that intense NIR emission arises from dopant-induced d–d transitions. In addition, the as-synthesized NIR-emitting perovskites retain 58% of the photoluminescence intensity at 425 K compared to 300 K. The NIR LED light source fabricated by the NIR-emitting samples exhibits promising potential for application in NIR spectroscopy analysis, night vision, and nondestructive testing. This work provides insights into the electronic transitions in Mo 4+ -activated broad-band NIR-emitting perovskites and opens up a new horizon for designing high-performance broad-band NIR luminescence.