The Influence Of The Improved Perovskite Morphology And The Optimized Hole Transporting Layer On Performance Of Perovskite Solar Cells

The perovskite morphology and hole transport layer play the vital role in the photoelectric performance of perovskite solar cells.In our paper,the active layer morphology is optimized by using mixed solvent vapor of acetic acid with chlorobenzene,the conductivity and transmittance of the hole transport layer(HTL)are modified by coating DMSO on PEDOT:PSS layer.The effect and mechanism of the performance of perovskite solar cells have been studied,main works are as follows below.Firstly,in order to increase the grain size of the perovskite thin film,improve the crystallinity of the perovskite,and reduce the defects in the perovskite thin film,a new route is developed in this paper to prepare CH3NH3PbI3(MAPbI3)films with a better morphology and crystallization to increase the performance of the perovskite solar cells.This method includes the spin coating of the perovskite films with the precursor solution of PbI2 and CH3NH3I at the molar ratio 1:1 and the thermal annealing(TA).The TA is the thermal-induced process that conducted to realize the grain growth of perovskite with solvent evaporation.In addition,the mixed solvent vapor treatment in the acetic acid with chlorobenzene(HAc/CB)improves the morphology and crystallization of perovskite films further.As a result,the photovoltaic device based on the perovskite film treated by mixed HAc/CB solvent exhibits the best efficiency of 13.15%in comparison to the control device with 11.44%under AM 1.5G irradiation(100 mW.cm-2).Secondly,the role of HTL is key to optimize the performance of perovskite photovoltaic devices.We introduce the method of the DMSO solvent coating PEDOT:PSS to improve the conductivity and transmittance of PEDOT:PSS simultaneously.The results are as show:(1)After the DMSO coating treatment with PEDOT:PSS,the conductivity of the PEDOT:PSS increases from 2.43 ×10-3 to 3.65×10-3mS/cm;(2)when the PEDOT:PSS was treated with DMSO,the transmittance of the PEDOT:PSS film is significantly increased,and the absorption of the perovskite layer is dramatically promoted.The DMSO-coated PEDOT:PSS is applied to the device preparation.The short-circuit current increases from 13.40 mA/cm2 to 19.41 mA/cm2,and the photoelectric conversion efficiency enhances from 10.23%to 12.19%in the device.These works provide the significant development potential of solvent vapor treatment process after the thermal annealing of perovskite thin films and solvent coating treatment PEDOT:PSS layer,which emphasizes an effective strategy to facilitate the efficient device performance of the planar heterojunction perovskite solar cells toward practical applications in the future.