Application Of Electrospinning Preparation Of ZnO Nanofibers Electron Transport Layer In Inverted Organic Solar Cells

In recent years the rapid development of organic solar cells,mainly through two directions to study to improve the performance of the cell,one is the electrical performance,another optical performance.The improvement in electrical performance is mainly achieved by improving the charge transfer and collection capability,while the improvement in optical performance is achieved by increasing the absorption of light.And the current cell structure improvement and improvement of the active layer has entered the bottleneck period,so people began to introduce nanostructures from these two directions to improve the performance of the cell,common methods are: First,the cell active layer by adding metal nanoparticles,The use of metal nanoparticles of the local surface plasmas to improve the absorption of light on the cell;Second,the electronic transport layer in the introduction of nano-structure,through the nano-structure to change the direction of transmission of electrons and shorten the electronic active layer to the electrode transmission time.In this paper,the nano-structure was added in the device to improve the performance from the electrical aspect.The ZnO nanofibers prepared by electrospinning were added to the electron transport layer of organic solar cells to study the effect of ZnO nanofiber electron transport layer on the active solar cell with inverted structure of PTB7: PC70 BM.The detailed study is as follows:1.The method of preparing ZnO nanofibers by electrospinning was studied.The ZnO nanofibers with variable diameter were prepared by changing the parameters of precursor solution of electrospinning,injection pump propulsion speed,receiving distance and output voltage of high voltage power supply.The PVP of ZnO / PVP nanofibers was investigated by the absorption spectra of ZnO / PVP nanofibers,the absorption spectra of ZnO,the absorption spectra of ZnO nanofibers and the absorption spectra of PVP.Effect of calcination time on the diameter of ZnO nanofibers.Through the experiment,the final PVP content is 3 g,the receiving distance is 12 cm,the propulsion speed of the syringe pump is 0.25 mL / min,the voltage size is 14.45 KV,15.45 KV,16.45 KV,17.45 KV,45~90 nm between the ZnO nanofibers.2.The design of the active layer for the PTB7: PC70 BM inverted structure of organic solar cell reference devices and experimental devices,and the design of electrospinning preparation of ZnO electron transport layer method.The performance of the device after adding ZnO nanofibers in the electron transport layer was improved from 6.3% to 6.8% by comparison with the electron transport layer prepared by ZnO nanoparticles.The effect of nanofibers on the performance of the nanofibers during the electrospinning process and the effect of the diameter of the ZnO nanofibers on the performance of the cells were investigated.By comparison,it is found that the Jsc of ZnO nanofibers is less than 30 s,and the effect of Jsc on the device is small.When the receiving time increases,Jsc is still improved but FF will decrease.At the same time,the diameter of ZnO nanofibers also affects the performance of the device.With the increase of the diameter of ZnO,the Jsc of the device is more obvious,and the FF will increase with the decrease of the diameter.3.By absorbing the absorption spectra of Zn O nanofibers and the absorption spectra of ZnO nanofibers with different diameters,the absorption of light from the ZnO nanofibers is stronger than that of the ZnO nanoparticles.The In the inverted structure of organic solar cells in the electron transport layer of light absorption enhanced,reducing the intensity of light into the active layer,is not conducive to the performance of the battery,but the performance of the battery is improved,indicating that the addition of ZnO nanofibers through Improve the electrical performance of the device to improve the performance of the battery.A single carrier device was designed to verify the improvement of the electrical performance of the device.The performance of the single carrier device was improved from 1.25 � 10-4 cm2V-1s-1 to 1.83 � 10-4 cm2V-1s-1.It is proved that the addition of ZnO nanofibers to the inverted structure of organic solar cells can improve the ability of the device to extract electrons and the transmission capacity of electrons from the active layer to the electrode.