Morphology Control Of Active Layer For Organic Solar Cells And Its Mechanic Research

In recent years,organic solar cells(OSCs)have attracted widespread attention,owing to their advantages of light-weight,low-cost,simple preparation process and semitransparency,which have become aroused general interest in OSCs research.For organic solar cell,high efficiency is the basis for industrialization,so the development of efficiency is the most important issue.In the past few decades,with the continuous exploration of materials and device engineering,many batteries with novel structures and excellent performance have been developed.Among them,controlling the morphology of the active layer to improve the generation,transport and collection of carriers is an important means to improve the performance of OSCs.The main research contents of this paper are as follows:(1)To explore the effect of ternary strategy on the morphology of the active layer of organic solar cells.Herein,high performance OSCs with over 18%efficiency using PM6 as donor and alloy-like acceptor containing two highly structurally similar acceptors(Y6 and Y6-1O)was obtained.In the study,we found that the absorption spectrum of Y6-1O can be complementary to that of Y6,which can maximize the photon capture in the ternary blend film and reduce the loss of light energy.Meanwhile,beneficial electron transport channels are established by the construction of cascaded energy levels of Y6 and Y6-1O in the ternary films.Compared with Y6 and Y6-1O based binary devices,enhanced charge mobility and suppressed charge recombination were observed in the optimal ternary OSCs,contributing to better performance.In addition,the efficient collection of charges and the optimization of the blend morphology of the active layer further enhance the device performance of the ternary OSC.This study presents a very promising ternary strategy with two highly compatible acceptors,which can improve the morphology of the active layer and increase the photocurrent to produce high efficiency OSCs.(2)To explore the effect of different post-processing processes on the morphology of the active layer of organic solar cells.Here,we analyze a systematic comparison of different post-processing treatments including untreated,thermally annealed(TA)and solvent vapor annealed(SVA)on the PM6 polymer donors and Y6 non-fullerene acceptors,compared their effects on device performance as well as morphological and optical and electrical properties.This solvent annealing processes can effectively improve the vertical distribution and aggregation of polymer donors and small molecule acceptors,then optimized the active layer film morphology,ultimately elevating PCE.Thus,one of champion efficiencies of 18.01% was achieved based on the PM6:Y6 binary OSCs.Based on the most optimized process,employing Cu(1nm)and Ag(15 nm)as the cathode to fabricate semitransparent OSCs can achieve,a remarkable PCE of13.07% with a corresponding 19.33% AVT,arriving at the largest LUE(2.53%).This result demonstrated to the function of SVA-treated in high-performance organic solar cell fabrication and provided a simple and promising way to optimize the active layer morphology is of quite a few significance,improved the power conversion efficiencies(PCEs)of organic solar cells(OSCs),Which provide a certain reference for the application of organic solar cells in buildingintegrated photovoltaics.