Ultra-high sensitivity graphene THz probe breakthrough
Institute of Nanotechnology and Nanobiology, Chinese Academy of Sciences, Key Laboratory of Nanodevices and Applications, Chinese Academy of Sciences Qin Hua team and the China Electronics Technology Group Co., Ltd. Thirteenth Institute of State Key Laboratory of integrated circuits, the successful access to high sensitivity Graphene terahertz detectors have the best sensitivity for their class of similar graphene detectors and are recently published in Carbon Materials magazine Carbon (116, 760-765 (2017)). Terahertz waves are electromagnetic waves with frequencies between infrared and millimeter waves and have important applications in information, biomedical and environmental detection fields. However, the development of terahertz technology has been subject to the bottleneck of the lack of technology for miniaturized high-power light sources and room temperature high-sensitivity detectors. At present, the technology of light source and detector has been greatly improved, and the technology of terahertz imaging is gradually entering the application fields of spectrum detection, biological imaging and human body security detection of dangerous chemicals. However, at the terahertz space of 0.3-3.0 THz Power glow and high sensitivity detection are still technical challenges. For example, a solid-state terahertz source operating at room temperature, emitting frequencies above 0.3 THz and having an output power on the order of 1 to 100 milliwatts is still in development. In another example, long-range real-time passive THz human security requires that the detector have a Noise Equivalent Power (NEP) of the order of 10-15 W / Hz 1/2 and that at present only superconducting detectors operating at cryogenic temperatures can approach The sensitivity. Therefore, the development of ultra-high sensitivity terahertz detectors working at room temperature is of great significance for the application of terahertz technology. Suzhou Nano's team has been working on the research of ultra-high sensitivity terahertz detectors at room temperature. Based on two-dimensional electron gas (2DEG) such as conventional semiconductor heterojunction (such as AlGaN / GaN) and graphene Hertz Mixing Detector. Dirac two-dimensional electronic materials such as graphene provide excellent characteristics such as high electron mobility, broadband optical absorption, highly tunable Fermi levels, bipolar carriers and their nonlinear transport for efficient mixing detection. The progress was made through cooperation between two key laboratories, taking advantage of high-quality double-layer graphene epitaxially grown on silicon carbide (SiC) substrates, design of highly efficient dipole antenna and detector, self-aligning antenna gate technology, The voltage responsivity of the graphene Self-mixing / Homodyne mixing detector in the 0.34 THz band is set to 30 V / W, which reduces the impedance of the detector to less than 203 Ω (detector thermal noise less than read Out of the circuit voltage noise), the measured noise equivalent power of about 163 pW / Hz1 / 2 (thermal noise limit the equivalent noise power of only 51 pW / Hz1 / 2). Based on this detector a clear perspective imaging of fresh leaves is achieved. At present, the joint team has further realized the Heterodyne mixing and Sub-harmonic mixing of graphene, and the maximum detection frequency reaches 0.65 THz. The cooperation broke through the equivalent noise (~ 207,000 pW / Hz1 / 2) of CVD-grown graphene-based detectors obtained by Suzhou Nanosciences team earlier (Chin. Phys. B 24, 047206 (2015) The level of detection sensitivity predicted in 2013 (Appl. Phys. Lett. 103, 173507 (2013)). The results show that the sensitivity of graphene detectors can be further increased by 2-3 orders of magnitude, but the formation of practical technologies remains to be further broken through key technologies such as design and manufacturing. The research and development of terahertz detectors have been supported by National Natural Science Foundation of China (No.,,), nano-fabrication platform of Suzhou Institute of Nanoscience and Technology, testing and analysis platform and Superconductivity Institute of Nanjing University. Kitchen And Dining,Multifunction Electric Health Pot,Stainless Steel Electric Health Pot,Electric Heating Soup Kettle GUANGDONG DEERMA TECHNOLOGY CO., LTD. , https://www.nbguangdongdeerma.com