Net Gain at the Near‐Infrared from CsPbBr₃ Quantum Dots Sensitized Nd³⁺‐activated Tellurite Glass Under Solar Excitation

Abstract

Lanthanide ions (Ln3+) doped near‐infrared (NIR) phosphors play a critical role in applications requiring a compact, reliable, and economical NIR light source, but as yet they suffer from weak and narrow‐band absorption because of intrinsic photophysical limitations of Ln3+. Here, CsPbBr3 perovskite quantum dots (PQDs) and Nd3+ co‐doped tellurite glassy phosphor is designed to significantly upgrade the NIR photoluminescence (PL) efficiency of Ln3+. Benefiting from the sensitization effect of the PQDs on Nd3+, the PL excitation band of Nd3+ is greatly extended, permitting far more excitation channels that are impossible for conventional Nd3+‐doped glass phosphors. Such glassy phosphors also show a good stability, and when coupled with a commercial UV (or blue) chip, a compact and low‐cost NIR phosphor‐converted LED (pc‐LED) is constructed with a photoelectric conversion efficiency of 2.25% and an output power of 2.55 mW. A proof‐of‐concept demonstration for night vision application is given using the NIR pc‐LED. The excellent overlap with the solar spectrum in the visible portion inspires us to explore the possibility of sunlight excitation, and a net gain of ≈5 dB cm−1 is obtained near the 1064 nm. The implications of the present study are enormous considering diverse combinations of PQDs and Ln3+ in GCs.