Synthesis And The Photoelectric Properties Of One-dimensional ZnO Composite Nanostructures

As an important renewable energy,solar cells have unique advantages for application.Dye-sensitized solar cells(DSSCs)have attracted widespread attention in the global scientific community due to its unique advantages such as high efficiency,low cost,green and environmental friend.As a direct wide band-gap semiconductor,zinc oxide(ZnO)nanostructures have potential applications in many fields,because of its unique physical and chemical properties.Vertically aligned ZnO nanowire arrays have attracted much attention because of their one-dimensional structure and unique properties.Synthesis of nanowires of good morphology and quality by controlling growth conditions is the key to improving the performance of the applied devices.In addition,they can be used as the counter electrode in DSSC.As a traditional electrode material,Pt has limited its large-scale application due to its high cost.As a result,various non-Pt counter electrodes have attracted widespread attention and application.Based on the one-dimensional ZnO nanowire arrays,the major research includes the following aspects:(1)Vertically ordered and well crystallized long ZnO nanowire arrays were synthesized on FTO glass substrate by a microwave-assisted hydrothermal method,and the defects controllable ZnO nanowire arrays can be grown in a short time.By means of adjusting the amount of hexamethylenetetramine(HMTA),it is found that rather low concentration of the raw materials of HMTA is necessary to avoid the brush defects on the nanowires arrays,which is also helpful to reach the maximum length growth rate up to 6.0 micron per hour.The sample is characterized by SEM.The results show that this method can reduce the defects and impurities on the surface of nanowires and increase the specific surface area of nanowires,thus increasing the amount of light absorption and improving the efficiency of the battery.When the prepared sample was used as the photoanode of the DSSCs,the test results of the photovoltaic characteristics showed that the conversion efficiency was as high as 1.55%,which is much higher than the traditional ZnO nanowire array.(2)ZnO@MoS2 nanocomposite structure is prepared based on the preparation of ZnO nanowire arrays.The ZnO nanowire arrays are encapsulated by pulse laser deposition technology,and the different thickness of the shell can be controlled by controlling the number of sputting pulses.Afterwards,the MoO3 on the surface of ZnO nanowire arrays is vulcanized as MoS2 by vapor phase method,and the aligned ZnO@MoS2 core-shell nanowire arrays were synthesized.When the prepared sample was used as the counter electrode of a DSSC,the IV test results showed that the short circuit current and open circuit voltage were high,and the fill factor and efficiency were comparable to Pt.