Lanthanide near-infrared emission and energy transfer in layered WS2/MoS2 heterostructure

Abstract

Lanthanide ions have attracted great attention due to their distinct photonic properties. The optoelectronic properties and device performance are greatly affected by the interfacial coupling between the layered van der Waals heterostructure, fabricated with two or more transition metal dichalcogenide (TMD) layers. In this work, lanthanide-doped WS2/MoS2 layered heterostructures have been constructed through two synthesis steps. The doped thin films are highly textured nanosheets on wafers. Importantly, the as-prepared heterostructure exhibits efficient near-infrared emission in the range of the telecommunication window, owing to energy transfer between lanthanide ions in the two TMD layers. The use of the layered heterostructure allows the decrease of deleterious cross-relaxation due to homogeneous doping or concentration quenching. The energy transfer process was further elaborated in this work. The results suggest that lanthanide ions can effectively extend the emission band of TMD thin films and their heterostructures. The doped TMD heterostructure is highly favourable for constructing atomically thin near-infrared photonic devices. 镧系离子由于其独特的光子特性而备受关注.二维层状范德 华异质结的光电特性和器件性能受到界面耦合的极大影响,质结通常是由两层或多层过渡金属二硫化物(TMD)堆叠而成.本文通过两步合成构建了镧系离子掺杂的层状WS2/MoS2异质结.该异所制备的掺杂薄膜是在晶圆衬底上生长的高度织构纳米片.更重要的是,由于两个TMD层中镧系离子之间的能量转移, 层状异质结的结构减少了因均匀掺杂或浓度猝灭而引起的无益交叉松弛, 所制备的堆叠异质结能够在近红外通讯窗口产生高效的光子发射. 镧系掺杂和能量转移的研究结果表明, 镧系离子可以有效地扩展TMD薄膜的发射波段及其异质结构. 本工作所发展的镧系掺杂TMD异质结有助于进一步研究原子级超薄近红外光子器件.