Abstract-THz Photonics in Two Dimensional Materials and Metamaterials: Properties, Devices and Prospects

Jinhui Shi,  Zhongjun Li,  David K. Sang,  Yuanjiang Xiang,  Jianqing Li,  Shuang Zhang,  Han Zhang

http://pubs.rsc.org/en/content/articlelanding/2018/tc/c7tc05460b#!divAbstract

Terahertz radiation refers to a broad electromagnetic spectrum range between microwave and infrared waves, which is also known as terahertz gap due to inadequate materials and technologies for its generation and manipulation. Atomically thin two dimensional (2D) materials such as graphene, black phosphorus (BP) and transition metal dichalcogenides (TMDs) provide a powerful platform for manipulating the propagation and detection of terahertz waves. Furthermore, hybrid meta-materials that feature the combination of artificially engineered meta-materials and 2D materials greatly facilitate dynamic modulation or manipulation of THz radiation towards novel terahertz applications. Herein, we review recent progress on 2D materials in the terahertz domain and hybrid metamaterials with engineered functionalities through the incorporation of graphene, TMDs and BPs. The emerging THz devices based on the modulation, nonlinearity, filtering, and Plasmonics of 2D Materials and Metamaterials will be highlighted, and a brief discussion with perspectives and the remaining challenges will be concluded.

Abstract-Toward Sensitive Room-Temperature Broadband Detection from Infrared to Terahertz with Antenna-Integrated Black Phosphorus Photoconductor

http://onlinelibrary.wiley.com/doi/10.1002/adfm.201604414/abstract;jsessionid=6D6EEA515BD415551858CA0C703C0EFC.f01t01?systemMessage=Wiley+Online+Library+Journal+subscribe+and+renew+pages+for+some+journals+will+be+unavailable+on+Wednesday+11th+January+2017+from+06%3A00-12%3A00+GMT+%2F+01%3A00-07%3A00+EST+%2F+14%3A00-20%3A00+SGT+for+essential+maintenance.+Apologies+for+the+inconvenience

Graphene-like two-dimensional materials (graphene, transition-metal dichalcogenides (TMDCs)) have received extraordinary attention owing to their rich physics and potential applications in building nanoelectronic and nanophotonic devices. Recent works have concentrated on increasing the responsivity and extending the operation range to longer wavelengths. However, the weak absorption of gapless graphene, and the large bandgap (>1 eV) and low mobility in TMDCs have limited their spectral usage to only a narrow range in the visible spectrum. In this work, we demonstrate for the first time a high-performance, antenna-integrated, black phosphorus (BP)-based photoconductor with ultra-broadband detection from the infrared to terahertz frequencies. The good trade-off between the moderate bandgap and good mobility results in a broad spectral absorption that is superior to that of graphene. Different photoconductive mechanisms, such as photothermoelectric (PTE), bolometric, and electron–hole generation can be distinguished depending on the device geometry, incident wavelength, and power. Especially, the photoconductive response remains highly efficient, even when the photon energy is extended to the terahertz (THz) band at room temperature, which is driven by the thermoelectric-induced well. The proposed photodetectors have a superior performance with an excellent sensitivity of over 300 V W−1, low noise equivalent power (NEP) (smaller than 1 nW Hz−0.5(10 pW Hz−0.5) with respect to the incident (absorbed) power), and fast response, all of which play key roles in multispectral biological imaging, remote sensing, and optical communications.