Research on Synthesis of Graphene by APCVD and its Design to Spectral Splitting Functions

石墨烯是一种新型的超薄超强碳纳米材料,其二维结构是由多个正六边形组合而成，如蜂巢一样,其厚度只有一个碳原子大小,约为0.335nm,是石墨、富勒烯和碳纳米管等其他碳基材料的构成单元。石墨烯的力学、电学、光学等特性都十分优秀，它是目前强度最大的材料，又是一种有极高迁移率的零带隙半导体材料，单层石墨烯对可见光的吸收率为2.3%，能在室温下发生量子霍尔效应等等。由于石墨烯的这些优异性能,使得石墨稀在光谱分析仪器、半导体材料、激光器件等领域有着光辉的应用前景。 本文对现有的几种主流石墨烯制备方法进行比较，决定采用常压化学气相沉积法在铜衬底上进行石墨烯制备研究，通过建立完整的实验装置和优化实验过程中的...Graphene is a new type of ultra-thin super carbon nano materials. The two-dimensional structure is composed of a plurality of hexagonal combination, such as honeycomb . Its thickness is only one carbon atom size, about 0.335nm. Graphite, fullerene and carbon nanotubes and other carbon based materials to form a single element. Mechanics, graphene electrical, optical properties are very good, it is ...学位：工程硕士院系专业：物理与机电工程学院_机械工程学号：X200918201

Study of Graphene Tunable Infrared Spectroscope Photoelectric Conversion Integrated Devices

提出了一种基于石墨烯材料的、串联结构的、纳米尺度的单色器与光电转换一体的集成器件。对石墨烯外加偏置电压使其费密能级偏离电荷中性点,偏离的大小决定石墨烯载流子带间跃迁的光子能量阈值。测量光生载流子的变化,可以实现石墨烯光谱吸收特性测量;设计两级串联且外加不同偏置电压的石墨烯与光波导集成的结构,实现窄带光波信号的光电转换和测量;改变偏压可改变通带频率和带宽,实现光谱扫描电信号输出,即得到了石墨烯可调谐光谱分光器件,可取代光谱仪中的单色器和光电转换器,使红外光谱仪实现小型化。The device with graphene material,series structure and nano scale to be integrated of monochromator and photoelectric converter was presented.The graphene was applied the bias voltage to make its Fermi level to deviate the charge neutratity point(CNP).The deviation magnitude is related to the threshold energy of the interband transition of graphene carriers.The measurement of graphene spectral absorption characteristics was realized by measuring the changes of thephotogenic charge carriers.The devices of graphene integrated with optical wave guide were designed with two stage series and different bias voltages,then the photoelectric conversion and measurement of the narrow band light wave signal were achieved.The passband frequency and bandwidth were changed by shifting the bias voltages,the spectral scanning electrical signal output was realized,and a tunable grapheme spectroscope was achieved.It can replace the monochromator and photoelectric converter in spectrometers and miniaturize the infrared spectrometer.国家自然科学基金资助项目(61172046); 福建省自然科学基金资助项目(2011J01363

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies