Preparation Of Znic Oxide Micro-nanostructure And Its Application In Organic Solar Cells

Polymer solar cells have attracted widespread attention due to its simple makingprocess, low cost, environmental friendliness and capability of large-scale production.However, polymer solar cells have poor stability and organic polymers own poor carriermobility. The thickness of the active layer is limited by carrier mobility that results inlow visible light absorption thus no effective utilization of sunlight. Inserting a porouszinc oxide nanofilm in polymer solar cells to enhancing visible light absorption wasproposed in this paper. This paper shows the preparation of zinc oxide nanofilm and theapplication of zinc oxide nanofilm in polymer solar cells. The major research content isas follows:Compact zinc oxide nanofilm was prepared by the sol-gel method andcharacterized by X-ray diffraction, scanning electron microscope and energy dispersivespectroscopy. The best compact zinc oxide nanofilms were obtained if the sol filmswere progressed by a heat treatment at500°C for3h.Based on the preparation progress of compact zinc oxide nanofilm, polyethyleneglycol was used as template to prepare the porous zinc oxide nanofilms which have a lotof micro-nanostructures. Influencing factors was investigated during the preparation.The best porous zinc oxide nanofilm contains uniformly distributed porous structures.The diameters of these structures are among200nm-300nm and the pore spacing iswithin200nm-500nm. The porous zinc oxide nanofilms meet well with therequirements of the grating structure which can be used in the polymer solar cells.The prepared zinc oxide thin films were used to prepare the polymer solar cellswhich use P3HT/PCBM as the active layer. Optical test and device efficiency test in thiscomparative study indicate that porous zinc oxide nanofilms that are used as gratingstructures can effectively improve the visible light absorption in the polymer solar cells,reduce the incident light reflectivity, and improve optical properties of polymer solarcells.In addition, ZnO/P3HT organic-inorganic hybrid solar cells were prepared. In thiskind of hybrid solar cell, the device performance is significantly influenced by themodifying of the active layer, the thickness of zinc oxide nanofilms and the morphologyof zinc oxide nanofilms. And this result further verifies that the grating structuresoffered by the porous Zinc oxide nanofilms can improve the performance of solar cells.