THE TEST OF APPLYING RADAR TREC WIND IN THREE-DIMENSIONAL VARIATIONAL ASSIMILATION

The application of radar–derived TREC wind to 3DVAR assimilation system of GRAPeS-3DVardeveloped by Chinese Academy of Meteorological Sciences is introduced. The resulting fundamental feature isestimated when radar TREC wind is assimilated into GRAPeS-3DVar system. It was found that radar TRECwind has better potential of the application in GRAPeS-3DVar system and can effectively improve the analyzedresults. Moreover a numerical experiment is performed in which tropical cyclones make landfall and transform;it also showed that the predicted effect can be improved when the radar TREC wind is added into GRAPeS-3DVar system.

Organic photodetectors based on transparent electrodes for application in ultraviolet light detection

A high performance heterojunction organic ultraviolet photodetector based on NPB and Bphen has been fabricated. A trans- parent conducting polymer PEDOT：PSS coated quartz substrate instead of ITO coated glass substrate as anode is propitious to detect shorter wavelength ultraviolet light. As a result, the device shows a low dark current density, a high responsivity of 502 mA/W and a detectivity of 2.67x1012 cm Hz1/Zfw which is illuminated by a 220 nm ultraviolet light with an intensity of 1.6 mW/cm2. Moreover, the performance of the PEDOT：PSS transparent electrode device is better than the semi-transparent A1 electrode device electrode because of the higher transmittance and electrode properties.

Reducing current fluctuation of Cs3Bi2Br9 perovskite photodetectors for diffuse reflection imaging with wide dynamic range

Recently,the newly booming metal halide perovskites have attracted extensive attention worldwide due to their outstanding optoelectronic performance,and are expected to be ideal candidates for photodetectors(PDs).However,there is still lack of perovskite PDs-based imaging devices coming into commercialization stage,due to some practical reasons including toxicity brought by lead-based perovskites and the large light current fluctuations.In this paper,for the first time we fabricate a lead-free Cs3Bi2Br9 perovskite PD,and build a prototype of this perovskite PD-based imaging system with diffuse reflection imaging mode.Moreover,we propose a new parameter F related to light current fluctuation to evaluate imaging performance of a PD especially for weak diffuse light condition,and prove its usability by comparison of unoptimized lead-free Cs3Bi2Br9 perovskite PD and atomic layer deposition(ALD)optimized Cs3Bi2 Br9 PD.ALD-optimization can improve the quality of perovskite film and suppress the dark current and current fluctuation.Finally,we obtain satisfactory diffuse reflection images of 2D and 3D objects with wide dynamic range.Therefore,the ALD-optimized Cs3Bi2Br9PD has addressed two major concerns about perovskite PDs-based imaging devices,that may extend application of perovskite materials and improve imaging quality.

High-performance flexible and broadband photodetectors based on PbS quantum dots/ZnO nanoparticles heterostructure

Flexible and broadband photodetectors have drawn extensive attention due to their potential application in foldable displays, optical communications, environmental monitoring, etc. In this work, a flexible photodetector based on the crystalline PbS quantum dots(QDs)/ZnO nanoparticles(NPs) heterostructure was proposed. The photodetector exhibits a broadband response from ultraviolet-visible(UV-Vis)to near infrared detector(NIR) range with a remarkable current on/off ratio of 7.08×10^3under 375 nm light illumination.Compared with pure ZnO NPs, the heterostructure photodetector shows the three orders of magnitude higher responsivity in Vis and NIR range, and maintains its performance in the UV range simultaneously. The photodetector demonstrates a high responsivity and detectivity of4.54 A W-1and 3.98×10^12Jones. In addition, the flexible photodetectors exhibit excellent durability and stability even after hundreds of times bending. This work paves a promising way for constructing next-generation high-performance flexible and broadband optoelectronic devices.