Abstract-Ultrastrong Terahertz Emission from InN Nanopyramids on Single Crystal ZnO Substrates

Huiqiang Liu, Zuxin Chen, Sheng Chu,Xuechen Chen, Min Liu, Nan Peng, Guang Chu, Feng Huang, Rufang Peng

http://onlinelibrary.wiley.com/doi/10.1002/adom.201700178/full

The creation of high efficiency and room temperature terahertz (THz) emitters has long been expected in both scientific and industrial communities. Despite the recent progress in THz source such as quantum cascade lasers, high efficiency THz emitters capable of operating at room temperature are still elusive. Indium nitride (InN), a narrow bandgap semiconductor, has emerged as a promising THz emitter due to its unique electronic properties. However, the efficiency of InN THz emitters reported up to now is still far from theoretically predicted because of inadequately engineered electrical conduction and radiative coupling. In this study, the authors report a novel, high performance THz emitting structure consisting of nanoengineered InN micro/nanopyramid arrays on a single crystal zinc oxide (ZnO) substrate. With improved electronic conduction from Zn diffusion induced doping and enhanced radiation coupling benefiting from uniquely structured geometry, the InN nanopyramids yielded THz emission intensity is close to an order of magnitude stronger than that of p-type indium arsenide (InAs). These findings prove that InN is a promising THz material and of wide importance in material science, optical engineering sectors, etc.

Abstract-Terahertz photodetectors arrays based on large scale MoSe2 monolayer

Huiqiang Liu,   Zuxin Chen,   Xuechen Chen,   Sheng Chu,  Jingwen Huang and   Ru-Fang Peng  

J. Mater. Chem. C, 2016, Accepted Manuscript

DOI: 10.1039/C6TC02748B

http://pubs.rsc.org/en/Content/ArticleLanding/2016/TC/C6TC02748B#!divAbstract

Large domains of monolayered transition-metal dichalcogenides (TMDCs) have emerged as exciting material systems because of their potential to provide a platform for ultrathin circuits and optoelectronics systems. Here we report ambient pressure chemical vapor deposition (CVD) growth of large scale MoSe₂ film for terahertz (THz) applications. Arrays of 100×60 µm MoSe₂rectangle layers were etched out and field effect transistors (FETs) were fabricated on these arrays. The device exhibits current on/off ratio of ∼10⁴. The THz photoresponse of the devices was studied and demonstrated the THz responsivity of ~38 mV/W, suggesting that TMDCs can be promising materials for long wavelength optoelectronics applications.

Abstract-Terahertz detectors arrays based on orderly aligned InN nanowires

Xuechen Chen, Huiqiang Liu, Qiuguo Li, Hao Chen, Rufang Peng, Sheng Chu, Binbin Cheng

http://www.pubfacts.com/detail/26289498/Terahertz-detectors-arrays-based-on-orderly-aligned-InN-nanowires

Nanostructured terahertz detectors employing a single semiconducting nanowire or graphene sheet have recently generated considerable interest as an alternative to existing THz technologies, for their merit on the ease of fabrication and above-room-temperature operation. However, the lack of alignment in nanostructure device hindered their potential toward practical applications. The present work reports ordered terahertz detectors arrays based on neatly aligned InN nanowires. The InN nanostructures (nanowires and nano-necklaces) were achieved by chemical vapor deposition growth, and then InN nanowires were successfully transferred and aligned into micrometer-sized groups by a "transfer-printing" method. Field effect transistors on aligned nanowires were fabricated and tested for terahertz detection purpose. The detector showed good photoresponse as well as low noise level. Besides, dense arrays of such detectors were also fabricated, which rendered a peak responsivity of 1.1 V/W from 7 detectors connected in series.