| Organic solar cells（OSCs）have great potential in in printing and roll-to-roll processes due to their unique advantages such as light weight,flexibility,and semitransparency.Subsequently,owing to the unique advantages in combining energy storage and visual function,semitransparent OSCs（ST-OSCs）have attracted extensive attention in recent years.Compared with conventional OSCs,ST-OSCs show a broad application prospect since their good light transmittance in the visible region.The pseudo-planar heterojunction（PPHJ）structure is more suitable for industrial large-area printing process than the bulk heterojunction（BHJ）structure due to its characteristics that the donor and acceptor layers can be prepared independently.However,since the same solvent used for the donor and accepto layer,the active layer films based on PPHJ structure do not have significant differences from the films based on structure.Moreover,the power conversion efficiency（PCE）of semitransparent devices is still lag behind opaque devices,and the trade between the PCE and transmittance of photovoltaic windows is difficult to be weighed.The resistance of organic photovoltaic windows to the natural environment is also crucial in practical applications.In this thesis,based on the selection of active layer materials and structures,a ternary PPHJ strategy is utilized to explore the relationship between active layer structure,morphology and device performance,and enhance the water resistance of semitransparent solar windows through encapsulation technology.The specific research work and results are as follows:1.After incorporate ICBA into the PM6/IT-4F system,the large-area high-performance ternary OSCs are printed by a PPHJ strategy,which can optimize the morphology of active layer films for better charge transfer and thermal stability.From the perspective of practical applications,this ternary PPHJ strategy is certified to be an effective strategy to amplify the vertical phase separation of organic semiconductor during scalable printing methods,leading a preeminent thermal stability and performance.Moreover,qualitative morphological measurements are employed to intuitively confirm that the high performance and good thermal stability root in the optimized vertical phase separation and enhanced crystallization.Accordingly,the large-area devices（1.05 cm2）fabricate by sequential blade casting（SBC）show an enhanced PCE of 14.25%as compared to the BHJ devices（13.73%）.2.The PPHJ structure is incorporated to fabricate organic solar windows during the printing process.From the perspective of photoelectronics,the PPHJ structure accurately improves the average visible transmittance（AVT）value while boosting the PCE of the solar windows.The optical loss in the ST-OSCs is effectively reduced by the incorporation of PPHJ structure.Compared with the BHJ structure,the active layer based on PPHJ structure has relatively less D/A interfaces in active layer,which can decrease the light scattering and parasite absorption.And the accumulation of cyaneous polymer donor at the bottom facilitates the reduction of reflection loss,contributing to the improvement of light utilization.Accordingly,the semitransparent devices based on PM6/ICBA:Y6 afford a maximal efficiency of 14.62%,with a considerable AVT of 20.42%.Moreover,the universality of PPHJ structure in preparation of ST-OSCs is demonstrated by introducing the PPHJ structure in two other systems.Furthermore,quantitative simulation test is employed to intuitively confirm that the superhydrophobic patterned soft insertion layer（PSIL）can function as moisture barriers without any optical loss.And the encapsulated large-area organic solar windows achieve a stabilized efficiency of 13.34%.The PCE of the unilateral broken solar windows sealed by PSIL can retain 70.6%of the initial efficiency after being placed under simulated rainfall conditions for 1200 h at room temperature.3.The non-conjugated polymer acceptor（PTClo-Y）is added as a third component to PM6/Y6 system for high-performance large-area ternary OSCs based on PPHJ structure.Employing PTClo-Y as the third component is motivated by the good miscible and complementary absorption spectra with both the PM6 and Y6,and PClo-Y possesses suitable energy level,which can form a cascade energy level alignment with PM6 and Y6 to facilitate charge transfer and minimize charge recombination.Meanwhile,the introduction of non-conjugated polymer acceptors has greatly improved the stability and mechanical properties of the ternary OSCs.The ternary devices prepared by blade-coating process with 15 wt%PTClo-Y in PM6/Y6system achieved a maximum PCE of 17.55%,an increased voltage(VOC)of 0.869 V,a short circuit current(JSC)of 26.18 m A cm-2 and a fill factor（FF）of 77.16%,significantly higher than the PM6/Y6 based binary devices（15.81%）.However,due to the low boiling point of chloroform,the solvent tends to evaporate during the preparation of large-area devices,which is not conducive to the blade coating process.Therefore,we further prepared high boiling point environmentally friendly non-halogenated solvent to process the devices.Using o-xylene as the solvent,the PCE of the small-area（0.04 cm2）and large-area（1.00 cm2）devices reached 16.23%and 15.32%,respectively.The enhanced performance of the PM6/PTClo-Y:Y6 based ternary devices is mainly attributed to the optimisation of the morphology,suitable vertical phase separation,reduced recombination losses and improved carrier lifetime in the active layer. |
