Study On Morphology Control And Ternary Blending System Of Organic Solar Cells Based On Porphyrin-containing Polymers

Organic solar cell?OSC?was born earlier but the road of its development was bumpy.At present,there are bottlenecks in device efficiency,stability and industrialization.Anyway,OSC has designable molecular structure of active layer materials,light weight,easy preparation,and can be made into flexible or translucent devices.Through the unremitting efforts of researchers all over the world,the power conversation efficiency?PCE?of single-cell device of OSC has exceeded 16%,but the goal of industrial production is still far away.At present,research on OSC mainly focus on the exploitation of new active layer materials and optimization of device processes.In order to expand the application of porphyrins in the field of organic solar cells,we have characterized two types of novel porphyrin-containing polymer donor materials,and carried out innovations in additive regulation and ternary blending devices.We optimized some device process and structure and further research on the application were studied.The main work contents are as follows:1.For new polymer donor materials PL1 and PL2,their optical,electrochemical and photovoltaic properties was characterized.On this basis,the morphology of binary active layers based on polymers PL1 and PL2 was optimized by using various additives.Then the idea of mixing additives was used to further improve the photovoltaic performance of PL2,and the final device efficiency reached 6.71%.In order to better play the excellent performance of PL2,we chose PBDB-T,a classical donor material that is complementary to PL2's absorption and matched with its energy level.Introducing PL2 into PBDB-T:PC71BM system to study ternary blending organic solar energy.The photovoltaic performance of the ternary device finally achieved a high PCE of 7.88%.2.For the new wide band gap polymer donor materials PPor-I and PPor-II,due to the introduction of porphyrins,the energy level and band gap of the polymer were adjusted to enhance the spectral absorption.Their optical,electrochemical and photovoltaic performance was characterized.The morphology of PPor-I:PC₇₁BM and PPor-II:PC71BM active layer films was controlled by DIO and NMP as solvent additives,which increased their device efficiency to 3.77%and 6.29%,respectively.In order to improve the photovoltaic performance of the device based on PPor-I:PC71BM active layer film,we used several ratios of DIO and NMP to adjust the morphology of PPor-I:PC71BM-based active layer film to further improve the PCE of the device,which increased to 5.36%,confirming the universality of the use of mixed additives.In addition,we also studied the photovoltaic performance of devices based on PPor-II:PC71BM active film with different thicknesses,and discussed the film thickness dependence of the device.Surprisingly,when the thickness of the active layer reaches210 nm,PCE of the device still has 5.79%,which is beneficial to the industrial roll-to-roll mass production.