Ultrathin Lanthanide-Based Metal-Organic Nanosheets with Thickness- and Temperature-Driven Light Emission

Abstract

Ultrathin light sources based on 2D materials are of fundamental importance for the design of planar optical and optoelectronic devices. Next to versatility in fabrication and integration of 2D materials with such devices, the efficiency of light emission at the nanometer scale remains a challenge. Here a geometrical approach is reported on to tune the light emission efficiency of 2D materials by mechanical exfoliation of lanthanide-based metal-organic frameworks (Ln-MOFs). For Ln-MOF nanosheets of a variable thickness (13.5–500 nm), it is discovered that a decrease in the thickness yields a 10–50 fold increase of photoluminescence (PL), while changing the temperature (300–7 K) additionally leads to a nonlinear growth of PL by 10–20 times. The reported temperature- and thickness-driven light emission by 2D Ln-MOFs opens prospects to design efficient, robust, and scalable ultrathin MOF-based light sources and optical sensors.