Study On Room Temperature Terahertz Photoelectric Detector Based On Graphite And Te Nanomaterials

As one of the most important materials in two-dimensional materials,graphene has become research hotspots in the field of optoelectronics because of its unique advantage of band-free,wide-spectrum absorption,ultra-fast carrier transport,and high carrier mobility since it is discovered in2004.Graphite nanosheets(GN)have more thickness compared with graphene,which can significantly improve the light absorption efficiency of the material,and helps to open up a new development path of optoelectronic application materials in the field of optoelectronic detection.As a new member of the two-dimensional material family,two-dimensional tellurium has strong air stability and high carrier mobility,which makes the two-dimensional tellurium a potential material for development and application in the field of optoelectronic detection.Terahertz(THz)detection technology is an important research content in the terahertz application field,and it has developed rapidly in different fields during recent years.Higher demands and challenges for terahertz detection technology are required.Therefore,the development of terahertz detection devices with high-sensitivity,fast-response,and room-temperature working has become the most important goal and direction of terahertz detection technology.This paper mainly studies new terahertz detectors based on two-dimensional materials,including high-performance room-temperature terahertz detectors based on graphite nanosheets and room-temperature terahertz detectors based on tellurium.The research content is as follos:(1)Graphite nanosheets are prepared by the way of micro-mechanical exfoliation,and we successfully fabricated a terahertz detector with high response rate and high response speed based on the mechanism of electromagnetic induction well(EIW)photoconductivity detection through the micro-nano preparation process.The responsivity and equivalent noise power(NEP)of the detector at a source frequency of 0.17 THz reached 5 k V/W and 24 p W/Hz^1/2 respectively.The response time of the detector is about 600 ns.At the same time,the detector can work at a wide modulation frequency of 1 k Hz to 20 k Hz.We discussed the effective receiving area of the detector by calculation.At the same time,we study on the detection mechanism of the detector by the way of excluding the effects of hot electron effect and bolometer effect on the photoelectric response of the device,and proving the theoretical calculation of electromagnetic induced well effect(EIW)is highly consistent with the EIW responsivity in experiment.It is believed that the EIW effect dominates the photoelectric response of the detector,which is the first application of the EIW effect in the detection of terahertz based on graphite nanosheets.(2)We prepared a high-quality tellurium rod by CVD,and fabricated a room temperature photoconductive terahertz detector with butterfly antenna and micron-width channel based on tellurium.The detector shows sensitivity over 6.98×10~6V/W at 0.032 THz and 1.79×10~4V/W at0.17 THz as well as NEP less than 0.259 p W/Hz^1/2 at 0.032 THz and 100 p W/Hz^1/2 at 0.17 THz at the modulation frequency of 1 k Hz.The response time of the detector is approximately 12.8?s.This study shows that two-dimensional tellurium has potential in the development and application of terahertz photoconductive detection.