Breakthrough in photoelectric detector research of

Breakthroughs have been made in the research of photodetectors at Hefei Research Institute of the Chinese Academy of Sciences

recently, Fei Guangtao, a researcher at the Institute of solid state physics, Hefei academy of material sciences, Chinese Academy of Sciences, has made a series of progress in the research of photoelectric detection of nano materials

SEM images of ordered arrays of V2O5 nanowires

related research work was published in phys Chem. Chem. Phys., 2016, 18(48): 、J. Mater. Chem. C, 2017, 5(6): 、Appl. Surf. Sci., 2017, 407: and J. mater Sci., (doi: 10.1007/s-z), some works have applied for Chinese invention patents

photoelectric detection plays an important role in medical diagnosis, biochemical analysis, environmental protection and other fields, and has a very wide application prospect. Improving the responsiveness, signal-to-noise ratio, response speed and practicality of the detector is the goal that researchers have been striving to pursue. Researchers of the research group have carried out a series of work around this goal, and made new progress in the preparation and performance optimization of nano materials for photoelectric detection: ordered arrays of vanadium oxide nanowires, vanadium dioxide/carbon nanotube composite films, ordered arrays of tellurium (TE) nanowires and lead telluride (PbTe) lattice nanowires were prepared respectively, and prototype detectors were constructed on the basis of the above materials. Relevant studies show that well crystallized nanowires can effectively reduce the influence of interface and defects in electron transport, and make the electron transport channel smoother. The performance of photodetectors based on aligned nanowires and lattice nanowires is significantly improved

the successful preparation of large-scale and highly ordered vanadium oxide nano low-carbon energy-saving related industries has also become a hot line array of concern in the rubber and plastic industry.

at present, most of the research on the photoelectric properties of nano materials is focused on a single nanowire. Others' research shows that the photoelectric properties of a single nanowire are better than conventional commercially available photodetectors. However, due to the small effective illumination area of a single nanowire, the photocurrent generated is very small, which requires very precise instruments to measure. If a single nanowire is arranged to form an ordered array, it can not only give play to the advantages of good photoelectric properties of nano materials, but also maximize the effective illumination area. Based on this, Fu Wenbiao and others of the research group prepared vanadium oxide nanowires with high crystallinity and few defects by hydrothermal method, and arranged them in order to successfully prepare large-scale and highly ordered vanadium oxide nanowire arrays, which can reach the order of square millimeter. The prepared V2O5 photodetector prototype device shows high detection performance at the incident wavelength of 450nm, the device response is 160.3 ma/w, and the detection rate is 6.5 × 108jones, the response time is 17-12 MS (J. mater. chem. C, 2017, 5 (6):). This work is of great significance to promote the preparation of array structures and applications in optoelectronic devices and other fields

v2o nanowire array photodetector performance

the vanadium dioxide/carbon nanotube composite film prepared has a strong infrared photoelectric response

the thermal infrared detector uses the thermal effect of infrared radiation to cause the temperature change of the detector to detect. Compared with photons, scientists from haydale composite solutions are currently working with Cobham technology service company For the cooperative infrared detectors of Airbus and BAE Systems, the advantage of thermal infrared detectors is that they are independent of the wavelength of incident light, can work at room temperature and have low cost. VO2 (m) has a large temperature resistance coefficient, and carbon nanotubes have the characteristics of small heat capacity and fast heat conduction. By combining VO2 (m) with carbon nanotubes to form a double-layer composite film, we can make full use of the advantages of both, quickly transfer the heat absorbed on carbon nanotubes to VO2 (m), and maximize the infrared photoelectric characteristics. They worked with Jiang Kaili, a professor of the nanotechnology research center of Tsinghua University, to prepare carbon nanotubes and VO2 bilayer composite films. The infrared photoelectric response of this VO2 (m)/carbon nanotube bilayer composite film is significantly higher than that of pure VO2 film (J. mater. sci., doi: 10.1007/s-z)

vo2 (m)/carbon nanotube composite film preparation and infrared detection curve

progress has been made in the research of tellurium nanowire ordered array infrared detectors

tellurium is a narrow band gap semiconductor material, with a band gap of about 0.35ev at room temperature, which has superior photoelectric properties. Compared with nanocrystalline films with a large number of interfaces, single crystal nanowires have fewer grain boundaries and weak scattering effect on photogenerated carriers. Therefore, they show good photoelectric properties, which is a hot spot of current research. As mentioned above, assembling a single nanowire in order to form an ordered array will not only give play to the advantages of good photoelectric properties of nano materials, but also maximize the effective illumination area

Zhong binnian et al. Prepared tellurium nanowires with uniform size and assembled them into a large area of ordered nanowire arrays. The prototype device of Infrared Photodetector Based on this large-area ordered tellurium nanowire array shows good infrared response characteristics. Compared with the disorderly arrangement of tellurium nanowires to simulate the test environment devices in which driverless vehicles cannot receive signals in tunnels, its response rate is greatly improved and the response time is shortened. This work reveals the great advantages of ordered array structure in photoelectric detection. This work was published in phys Chem. Chem. Phys., 2016, 18 (48): up

PCCP journal Vol. 18 No. 48 back cover

progress has been made in the research on the performance of infrared detection of lead telluride nanowires

the infrared detector based on lead telluride (PbTe) has the advantages of covering the mid and far infrared band, low detection noise, high quantum efficiency and high sensitivity, and has broad application prospects in infrared detection. At present, PbTe infrared detectors mainly exist in the form of thin films composed of nanoparticles, but the interface between nanoparticles in the thin films will hinder the electron transport, resulting in the degradation of detector performance. MSM photodetector is a metal semiconductor metal contact photovoltaic detector, which can be regarded as a pair of back-to-back Schottky barrier diodes. The dark current of this structure detector is usually very small. The research group Gong Xinxin and others combined the advantages of single crystal nanowires and MSM structure to build an infrared detector prototype device with PbTe single crystal nanowires MSM structure. The research shows that this detector prototype device has good cycle stability, and the response time is in the order of milliseconds, which is much faster than the thin film composed of particles (see appl. surf. sci., 2017, 407:)

photoelectric curve and response time curve of PbTe nanowire infrared detector

the above work has been supported by national major scientific research projects and a number of National Natural Science Foundation projects