Study Of Organic Solar Cells Performance Based On Interfacial Modification And Ternary Strategy

Organic solar cell（OSC）,due to its solution-processable simple preparation method,low cost,light and thin,flexible and translucent device characteristics,and industrial potential for large-area manufacturing,has huge development prospects and application value in the renewable energy field.In order to achieve the application of OSC,the power conversion efficiency（PCE）,stability amd lifetime of OSC need to be optimized further.All polymer based OSC obtains optimal bending resistance,but the PCE is pretty low.This thesis firstly adjusts the morphology to improve the performance through ternary strategy on the basis of the all polymer system.Secondly,it focuses on the influence of interface optimization on the device based on the PM6:Y6 system.The main contents are as follows:1.A polymer PTO2 is used as the third component and added to the all polymer system PBDB-T:N2200,in which the improvement of the performance of all polymer ternary OSCs is achieved.When the doping ratio of PTO2 is 10%,the short circuit current density(J_sc)of the device increases from 13.29 m A/cm² to 15.93 m A/cm²,the fill factor（FF）is optimized from 57%to 61%,and the power conversion efficiency（PCE）is enhanced from 6.14%to 8.33%.The study found that the addition of the PTO2 improves the electron transporting,modifies the morphology of active layer and forms the effective interpenetrating network structure,and finally makes J_sc and PCE effectively improved.2.A triphenyltriazine derivative mTPOTz based on arylphosphine oxygen is doped into the traditional electron transport layer ZnO.Firstly,the all polymer system PBDB-T:N2200 is adopted on the optimized ZnO transmission layer,and the FF achieved a significant increase from 55.5%to 63.0%.Subsequently,according to the findings mentioned before,high performance system PM6:Y6 is used as the active layer to explore the effects of mTPOTz to the device.Under the optimal doping ratio,the device can achieve an increase in PCE from 14.71%to 16.34%.Through a series of characterization and testing methods,it is found that the ZnO electron transport layer has higher conductivity and the higher electron mobility,which are benefit from the electron transport characteristics of the mTPOTz itself.In addition,mTPOTz improves the affinity of the ZnO electron transport layer surface,and optimizes the morphology of the active layer.This thesis studies an effective strategy to optimize the performance of the all polymer system,and also proposes an interface optimization strategy that is suitable for both the all polymer system and the small molecule system,which provides a referable idea for improving the performance of OSC.