利用金奈米柱提升單層與三層之二硫化鉬的電致發光與光致螢光

Abstract

提升弱發射體(像是二維原子層的二硫化鉬)的自發發射率是一項非常前端的應用，用於開發出下一個世代的高科技光電產品，如:可饒式的手機，超薄發光二極體，原子薄的光電電晶體，諸如此類。過鍍金屬硫化物中的二硫化鉬或二硒化鎢已經被成功的應用在場效電晶體中的通道材料，且展現出出色的效能在感測或是光電的科學領域。這裡，我們將報導利用金奈米柱的局域性表面電漿提升單層二硫化鉬的光致螢光。這些金奈米柱的共振吸收帶與二硫化鉬的發光波段有交疊，導致光致螢光有6倍的增強效果。基於金奈米柱與二硫化鉬的光致螢光耦合後造成自發發射增強的觀念，我們也製作出二硫化鉬的電致螢光元件(發光元件)並在通道處鋪上金奈米柱，使得電致螢光有2倍的增強。幸運地，這些吸附在發光元件通道的金奈米柱並未造成電特性惡化。我們這項工作建立起一個平台針對增強這些新興二維發光材料(像是過鍍金屬硫化物)的發光效率，使得在未來能應用在光電元件上。

Enhancing the spontaneous emission of a weak emitter, such as two dimensional atomic layers of MoS2, is an avant-garde research for developing the next generation of high-technology optoelectronic products, like flexible mobiles, ultrathin LED, atomically thin phototransistor, and so on. MoS2 or WSe2, transition metal dichalcogenides (TMDCs) semiconductor, have been successfully applied to channel materials for field-effect- transistors, outstanding performances in the novel scientific field of sensing and photonics. Here, we report localized surface plasmon enhanced photoluminescence of monolayer MoS2 by the gold nanorods. The resonance absorption bands of these gold nanorods overlaps MoS2 gain region a lot resulting in photoluminescence enhancement of ∽6-fold. Based on the concept of the coupling of gold nanorods and the photoluminescence of MoS2 resulting in the spontaneous emission enhancement, we also decorated the channel in MoS2 electroluminescent devices (light-emitting devices) with gold nanorods. The 2-fold enhancement of electroluminescence intensity are achieved. Luckily, these gold nanorods physically adsorbed on the channel of light-emitting devices has not caused the electrical properties to deteriorate. Our work builds up a platform to enhance the emitting efficiency in emerging two dimensional emitting materials, such as TMDCs, for application to optoelectronic devices in the future.