PtTe2-Based Type-II Dirac Semimetal and Its van der Waals Heterostructure for Sensitive Room Temperature Terahertz Photodetection
PtTe2-Based Type-II Dirac Semimetal and Its van der Waals Heterostructure for Sensitive Room Temperature Terahertz Photodetection
复制标题
用于灵敏室温太赫兹光电探测的 PtTe2 型 II 型狄拉克半金属及其范德华异质结构
作者：
Xu Huang;Guo Cheng;Zhang Jiazhen;Guo Wanlong;Hu Weida;Wang Lin;Chen Gang;Chen Xiaoshuang;Lu Wei
近年来，以石墨烯、黑磷、过渡金属二硫属化合物为代表的二维材料的光电性能取得了快速进展。尽管做出了巨大的努力，但由于缺乏带隙、暗电流和吸收能力之间的最佳性，能够实现更长波长、更高工作温度以及快速响应的光电探测技术仍然面临巨大的挑战。探索具有非平凡带输运的拓扑材料导致了诸如手性异常和磁光效应等量子化现象的特殊性质，这使得在更长波长下工作的先进光电器件具有新的可行性。在这项工作中，直接产生的光电流在低能量太赫兹（THz）波段在室温下实现了平面金属-PtTe 2-金属结构。结果表明，基于PtTe 2的蝴蝶结型平面接触的THz光电探测器具有较高的光响应度（1.6 A W− 1，无偏置电压），响应时间小于20 µs，而基于PtTe 2-石墨烯异质结的探测器可以达到1.4 kV W− 1以上的响应度，响应时间小于9 µs。值得注意的是，它已经可用于大面积成像应用。这些结果表明，拓扑半金属，如PtTe 2可以在太赫兹波段的高性能光电探测系统中实现的理想材料。
Recent years have witnessed rapid progresses made in the photoelectric performance of two‐dimensional materials represented by graphene, black phosphorus, and transition metal dichalcogenides. Despite significant efforts, a photodetection technique capable for longer wavelength, higher working temperature as well as fast responsivity, is still facing huge challenges due to a lack of best among bandgap, dark current, and absorption ability. Exploring topological materials with nontrivial band transport leads to peculiar properties of quantized phenomena such as chiral anomaly, and magnetic‐optical effect, which enables a novel feasibility for an advanced optoelectronic device working at longer wavelength. In this work, the direct generation of photocurrent at low energy terahertz (THz) band at room temperature is implemented in a planar metal–PtTe2–metal structure. The results show that the THz photodetector based on PtTe2with bow‐tie‐type planar contacts possesses a high photoresponsivity (1.6 A W−1without bias voltage) with a response time less than 20 µs, while the PtTe2–graphene heterostructure‐based detector can reach responsivity above 1.4 kV W−1and a response time shorter than 9 µs. Remarkably, it is already exploitable for large area imaging applications. These results suggest that topological semimetals such as PtTe2can be ideal materials for implementation in a high‐performing photodetection system at THz band.