Enhancing monolayer photoluminescence on optical micro/nanofibers for low-threshold lasing

Abstract

Although monolayer transition metal dichalcogenides (TMDs) have direct bandgaps, the low room-temperature photoluminescence quantum yields (QYs), especially under high pump intensity, limit their practical applications. Here, we use a simple photoactivation method to enhance the room-temperature QYs of monolayer MoS2 grown on to silica micro/nanofibers by more than two orders of magnitude in a wide pump dynamic range. The high-density oxygen dangling bonds released from the tapered micro/nanofiber surface are the key to this strong enhancement of QYs. As the pump intensity increases from 10−1 to 104 W cm−2, our photoactivated monolayer MoS2 exhibits QYs from ~30 to 1% while maintaining high environmental stability, allowing direct lasing with greatly reduced thresholds down to 5 W cm−2. Our strategy can be extended to other TMDs and offers a solution to the most challenging problem toward the realization of efficient and stable light emitters at room temperature based on these atomically thin materials.

Plasmon-driven nanowire actuators for on-chip manipulation

“…Fabrication of silica microfibres and metal nanowires. Silica microfibres and fiber tapers used in this work were drawn from standard fibers (SMF-28, Corning) by using a simple flame-heated method 38,39 . The diameters of microfibres were in the range of 1-3 μm.…”

Magnetic plasmon resonances in nanostructured topological insulators for strongly enhanced light–MoS2 interactions

“…Transition metal dichalcogenides (TMDCs), as a kind of 2D materials with unique semiconductor-like band structures, are regarded as a favorable platform for advancing next-generation optoelectronics due to the unique electric, mechanical and optical properties 31,32 . As a prototypical TMDC semiconductor, MoS 2 possesses a state transition from an indirect bandgap of 1.2 eV to a direct bandgap of 1.8 eV as it transforms from bulk to monolayer 31,33 sources [33][34][35] . However, the atomically thin layer with poor light-matter interactions hinders the substantial application of MoS 2 for light harvesting and emission 33,35 .…”

“…As a prototypical TMDC semiconductor, MoS 2 possesses a state transition from an indirect bandgap of 1.2 eV to a direct bandgap of 1.8 eV as it transforms from bulk to monolayer 31,33 sources [33][34][35] . However, the atomically thin layer with poor light-matter interactions hinders the substantial application of MoS 2 for light harvesting and emission 33,35 . Here, we innovatively integrate a MoS 2 atomic monolayer with a Sb 2 Te 3 TI nanostructure to explore the tailoring and enhancement of PL emission.…”

Direct‐Bandgap Bilayer WSe2/Microsphere Monolithic Cavity for Low‐Threshold Lasing

“…[ 14 ] Recently, we achieved the growth of large‐scale MoS 2 monolayers on microfiber cavities using CVD. [ 15 ] Particularly, the complete wrapping of the cavity with monolayers maximized the area overlap and contributed to excellent cavity performance.…”