Preparation Of Titanium Dioxide Thin Films And Perovskite Solar Cells By Electrostatic Spraying

Perovskite solar cell is a new type solar cells, solar cells using organic-inorganic hybrid materials as the active layer. It’s the power conversion efficiency has exceeded 20%, and is the most promising novel solar cell as for now. Liquid-phase fabrication technologies of perovskite solar cells are current research hotspots, and the main research direction for future mass production of the novel solar cells, because of the possibility to overcome the drawback of high cost for current mainstream Si-based solar cells and to realize low-cost and effective utility of solar energy.Electrospraying is a method to atomize liquid into tiny droplets using static electric force for spraying out. It is a new fabrication technology of micro-nano structures, with the merits of low-cost, capable of fabricate large-area samples, applicable for flexible substrates, therefore very suitable for industrial production. This article mainly explored the technical path of fabricating perovskite solar cells using electrospraying method, and compared it with the traditional spin-coating method, so as to pave the way for further research.Firstly we set up a electrospraying system, and used it to spray titanium dioxide sol. We characterized thin films fabricated using different parameters, and studied the impacts of spraying parameters to the morphology of the TiO2 thin film. Through optimization of the spraying parameters, we separately fabricated continuous and dense TiO2 thin film, as the blocking layer of the perovskite solar cells, as well as dense and porous TiO2 particle network, as the mesoporous layer of the perovskite solar cells. Then we used the blocking and mesoporous layers fabricated by electrospraying to fabricate complete perovskite solar cells samples, and used traditional spin-coating method to fabricate reference perovskite solar cells. During the fabrication process, we spin-coated the perovskite active layer and the hole transport layer, vacuum-evaporated the silver electrode, and optimized the fabricating parameters of each function layer. Finally we tested the main optoelectronic performance of the perovskite solar cells, and compared and analyzed the cells prepared by the two different methods. The test results showed that the electrospraying method can be used for fabrication of the blocking layer and mesoporous layer of the perovskite solar cells. The cells fabricated by this method showed performance comparable or superior to those fabricated by traditional spin-coating method, and the photoelectric conversion efficiency could reach 8.29%.