Preparation And Optimization Of Hole-conductor–free Fully Printable Mesoscopic Perovskite Solar Cell

Compared with conventional perovskite solar cell?PSCs?,hole-conductor–free fully printable mesoscopic PSCs has many advantages such as simple technology,low-cost and good long-term stability,which maks it possible for commercialization.Firstly,in this paper,preparation technology of hole-conductor–free fully printable mesoscopic PSCs had been explored.Then,the porosity and electron transport ability of carbon counter electrode?CCE?and TiO₂ layer were optimized and the preparation process of device was simplified.Details are listed as follows:The effect of preparation technology of TiO₂ layer and ZrO₂ layer,modified of TiO₂ layer,and sintering process on device were studied.It was revealed that the preparation process of paste has a significant effect on the thickness and roughness of film.The device got the best performance when the solid content and mass ratio of ethyl cellulose to terpineol of TiO₂ paste were 8%,1:16,and those of ZrO₂ paste were 12%,1:12.Mesoporous TiO₂ based on TiO₂ nano-sheets has good electron transfer capability while poor binding force with FTO.When based on TiO₂ nano-sheets and nano-particles,mesoporous TiO₂ has good electron transfer capability,porosity and better binding force with FTO.The cell with highest efficiency was obtained when the content of TiO₂ nano-sheets was 75%.Compared with conventional sintering process,the device based on co-sintering of spacing layer with CCE has good performance and long-term stability,which is helpful to shorten the preparation cycle of the dvice.The effect of preparation technology of CCE on solar cell was investigated.Then,the optimized of thickness,conductivity and porosity of CCE have been done.The results show that ZrO₂ acts as holdfast in CCE.Ethyl cellulose is a main influence factor for the film-forming ability and porosity of CCE.The thickness of CCE is an important factor to the devices and the PCE is highest when the thickness is 8?m.Carbon black could significantly affect the crystallinity of the perovskite ciystal and the conductivity and wettability wirh CH3NH3PbI3 precursor solution of CCE.It can be found that device based on EC300 J has the best efficiency.Polystyrene?PS?spheres acted as pore-forming agent.The porous structure obtained with the decomposition of the PS spheres on CCE is helpful for the CH3NH3PbI3 precursor solution permeate into the Ti O₂ layer.When the content of PS spheres is 10%,the device showed an efficiency of 4.49%.In a word,the PCE of device reached 4.88% when the thickness of mesoporous layer and spacing layer were 700 nm?500 nm respectively and a 8 ?m CCE based on EC300 J was employed.Finally,used as pore forming agent,the device has the best PCE when the content of PS spheres in carbon paste was 10 %.