| Over the past few decades,organic solar cells（OSCs）got rapid development,and power conversion efficiency（PCE）of small area OSCs in the laboratory scale has been over 12%.However,the functional layers of the high-performance OSCs are prepared by spin coating,and the performance of the the functional layers is often sensitive to the thickness,which limit their mass production.Therefore,in order to realize the industrialization of the OSCs,the technology of making films that can be matched with roll-to-roll（R2R）processing is required,such as blade coating,spraying,slot die coating and so on.Moreover,it is necessary to develop materials with thickness insensitivity.In this paper,we design several interface materials and active layer materials with thickness insensitivity and realize the high-efficiency large area OSCs devices by blade coating.In Chapter 2,we reported the development of cross-linkable and dual functional hybrid polymer ETLs（20%PN4N@x-N2200）by simply adding an amino-functionalized polymer dopant（PN4N）and a light crosslinker（bisPFPA）into a commercialized n-type semiconductor（N2200）matrix.The hybrid ETL possess improved electron mobility and photoconductivity due to n-type doping stemmed from electron transfer from amino groups of PN4N to the conjugated backbone of N2200.By using the blend of PTB7-Th:PC71BM as active layer,the inverted device based on the hybrid ETL can yield a PCE of around 10.07%.More interestingly,we find the hybrid ETL can not only be employed as cathode interlayer materials to modify ITO cathode,but also function as light harvesting acceptor to form miniature bilayer solar cells contributing to the overall device performance for the invert OSCs.This work provide new insights on function of ETLs and maybe open up a new direction for the design of new ETL materials and novel device architectures to further improve device performance.In Chapter 3,we obtained in-situ generated Au nanoparticles（Au@PN4N）by adding the appropriate amount of HAuCl4 into the amino-functionalized PN4N solution,which can be applied directly as the cathode interlayer in OSCs.When the quality of Au is 10%（i.e.10%Au@PN4N,Au NPs）,the PCE of the OSCs devices is optimal.In addition,we added Au NPs into the ZnO nanoparticles solution,and got the optimal hybrid interface material（Au NPs@ZnO）.As a result,the device performance showed less independence on its thickness.These results provided a new strategy for designing thickness-insensitive interface materials.In Chapter 4,we doped a small amount of NDI-PFNBr into a sol-gel derived ZnO film to fabricate an organic–inorganic hybrid ETL（NDI-PFNBr@ZnO）.It was found that the resulting organic–inorganic hybrid ETL showed apparently improved conductivity and acted as an effective cathode interlayer to modify indium tin oxide（ITO）transparent electrodes.As a result,by employing PTB7-Th:PC71BM as the photoactive layer,the inverted OSCs exhibited a champion PCE of 10.04%.Meanwhile,we also studied the effect of its thickness on the performance of OSCs devices.The results showed that when the thickness increased from 30 nm to 90 nm,the PCE of the device only dropped by about 12%,indicating that NDI-PFNBr@ZnO can be used as the thickness-insensitive ETL for large area OSCs device.In Chapter 5,we designed and synthesized two NT-based conjugated polymer（PBT6NT and PBT6T6NT）.Further temperature dependent solution UV-vis measurements indicated that PBT6T6NT is thermochromic while PBT6NT is non-thermochromic.The OSCs device based on them showed a PCE of 9.71%for PBT6NT and a PCE of 8.62%for PBT6T6NT.Moreover,the devices based on PBT6NT still maintained a PCE of as high as 8.6%when the thickness of active layer varied at the range of 100-460 nm.These results indicate that narrow band gap polymer containing naphthothiadiazole is very suitable for the production of large-area OSCs by roll-to-roll proccess in the future.In Chapter 6,we studied the effect of blade-coating parameters on device performance,and obtained high-performance small area OSCs devices based on NT812:PC70BM as thick-film active layer,with a PCE of 8.72%.Then,we obtained monolithic large-area devices by simply enlarging device area.However,with the increase of device area,the PCEs of monolithic large-area devices are greatly reduced.When device area increased from 0.04 cm2to 7.29 cm2,the PCEs of monolithic large-area devices decreased significantly from 8.5%to3.18%.Finally,considering the energy loss caused by the square resistance of ITO transparent electrode,we designed series connected module devices with effective device area of 4 cm2,consisting of two monolithic device（2cm*1cm,2 cm2）.Through reasonable design for the electrode,we obtained high-performance large-area module devices,with a PCE of as high as8.02%. |
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