论文标题
过渡金属二甲藻元化杂质的光致发光中的强烈定位效应
Strong Localization Effects in the Photoluminescence of Transition Metal Dichalcogenide Heterobilayers
论文作者
论文摘要
在过渡金属二分法（TMDC）及其异质结构中，各种激子相关的效应的出现启发了大量研究，并提出了几种可能的应用。通常，具有显微镜横向分辨率的标准光致发光（PL）被用来识别和表征这些激子现象，包括层间激子（IEXS）。我们研究了由（Mo，W）（S，S，SE）的去角质单层组成的Van der Waals异叶剂的本地PL签名，$ _ 2 $ _ 2 $ _ 2 $ tmdc家族具有高空间分辨率（降至30 nm），使用尖端增强的光效率（TEPL），具有不同的订单（TEPL），具有不同的订单（top/tobs/tobs/tobs/tobs/tobs/tops/tops/top/top/tops/top/tops/tops/top/tops/top/top/top/tops/tops/tops/top/top/tops/botiss and top/tops and。我们证明，其他PL信号可能会出现在报告的IEX转变的能量附近，这可能会干扰结果的解释。虽然我们可以区分并确认在MOS $ _2 $ -WS $ _2 $和MOSE $ _2 $ -WSE $ _2 $中与IEX相关的PL的存在，但我们在MOS $ _2 $ -WSE $ _2 $ _2 $ _2 $ heterobilayer的光谱中没有1.7-1.4 ev的Heterobilayer在1.7-1.4 ev（iexssssss of heterobilayer）中均未发现此类功能。我们将额外的信号分配给单个单层的PL，其中激子能量是由于水泡和纳米泡的形成而导致的局部菌株改变的，并且由于层的解耦，PL极大地增强。我们证明，即使是一个小至60 nm的单个纳米泡 - 因此，在原本平坦的异质层的微型PL频谱中诱导了这种可疑的PL特征。
The emergence of various exciton-related effects in transition metal dichalcogenides (TMDC) and their heterostructures has inspired a significant number of studies and brought forth several possible applications. Often, standard photoluminescence (PL) with microscale lateral resolution is utilized to identify and characterize these excitonic phenomena, including interlayer excitons (IEXs). We studied the local PL signatures of van der Waals heterobilayers composed of exfoliated monolayers of the (Mo,W)(S,Se)$_2$ TMDC family with high spatial resolution (down to 30 nm) using tip-enhanced photoluminescence (TEPL) with different orders (top/bottom) and on different substrates. We evidence that other PL signals may appear near the reported energy of the IEX transitions, possibly interfering in the interpretation of the results. While we can distinguish and confirm the presence of IEX-related PL in MoS$_2$-WS$_2$ and MoSe$_2$-WSe$_2$, we find no such feature in the MoS$_2$-WSe$_2$ heterobilayer in the spectral region of 1.7-1.4 eV, where the IEXs of this heterobilayer is often reported. We assign the extra signals to the PL of the individual monolayers, in which the exciton energy is altered by the local strains caused by the formation of blisters and nanobubbles, and the PL is extremely enhanced due to the decoupling of the layers. We prove that even a single nanobubble as small as 60 nm---hence not optically visible---can induce such a suspicious PL feature in the micro-PL spectrum of an otherwise flat heterobilayer.
