| Photovoltaic power is an important part of new energy sources.Because of the advantages of light weight,simple preparation process,processing by solution and being fabricated large area and flexible devices,organic solar cells have attracted a lot of attention from researchers to industry and developed rapidly in the past decades.The dissertation is dedicated to the synthesis of donor materials and electron transport materials for organic solar cells.In addition,the production and application of organic solar cells were investigated.It provides a guiding idea for the preparation and application of new high-efficiency,low-cost organic solar cells.The work mainly consists of the following parts:1.A small molecule donor material BDT（TVT-SR）2 based on the existing small molecule donor H11 was synthesized for all-small molecules organic solar cells with IDIC acceptor.Compared with H11,its absorption edge was red shifted to 680 nm,the lowest unoccupied molecular orbital level was lowered to-3.18 e V;and the hole mobility was increased to 1.34×10-4 cm2V-1s-1.The device based on BDT（TVT-SR）2:IDIC with D:A ratio of 2:1 was prepared.Without annealing,the photoelectric conversion efficiency of the device was 5.64%,with an open circuit voltage of 1.01 e V,a short-circuit current of 10.22 m A/cm2,and a fill factor of54.63%.After annealing,the device performance was greatly improved.The PCE achieved 11.10%,with an open circuit voltage of 0.98 e V,a short-circuit current of15.92 m A/cm2,and a fill factor of 71.15%.In addition,The device based on BDT（TVT-SR）2:IDIC also exhibited high stability.2.BDT-2T-DCV-ME with malononitrile end group and BDT-2T-CNAB with butyl cyanoacrylate end group were designed and synthesized as donor materials for all-small molecule organic solar cells.Compared with BDT-2T-DCV-ME,BDT-2T-CNAB has higher crystallinity;and its highest occupied molecular orbital and lowest unoccupied molecular orbital levels were slightly increased to-5.66 e V and-3.31 e V.However,the thermal stability of BDT-2T-CNAB was reduced.Under the optimal conditions,the highest photoelectric conversion efficiency of the device based on BDT-2T-DCV-ME:IDIC was 1.56%,with an open circuit voltage of 1.09 V,a short-circuit current of 5.09 m A/cm2,and a fill factor of 28.08%.The photoelectric conversion efficiency of the device based on BDT-2T-CNAB:IDIC was up to 6.17%,with an open circuit voltage of 1.03 V,a short-circuit current of 10.11 m A/cm2;and a fill factor of 59.08%.The poor charge generation and blend morphology of the BDT-2T-DCV-ME:IDIC blend membrane are mainly accounted for the low photoelectric performance.These results provid a new idea for designing high-performance small molecule donors.3.A new group of zwitterionic molecules named as G-P,G-C2,G-Si H,and G-Si were synthesized by a simple method,which can be used as the electron transport layer materals for organic solar cells.These molecules do not contain any conjugated structure,thus their transmittances of light are close to 100%in the range of 300 nm to 900 nm.At the same time,the absorption of light by the active layer material can be promoted.The work function of the Al cathode metal electrode material can be adjusted to the range between-4.21 e V and-4.09 e V,which was closer to lowest unoccupied molecular orbital level（-4.0 e V）of the acceptor material PC71BM.These materials have high electron transport rates from 7.92×10-3 cm2V-1s-1to 9.12×10-3 cm2V-1s-1.The short-circuit current of the organic solar cells based on this electron transport layer materials were greatly increased from 13.98 m A/cm2 to16.93 m A/cm2;and their photoelectric conversion efficiencis were also increased from 6.10%to 8.90%.4.Using a bottom-up cost model for single-junction organic solar cells,flexible single-junction solar cells,tandam organic solar cells,and flexible tandem solar cells,a detailed cost analysis was conducted.Under the setting conditions,in the industrial manufacturing scale,the manufacturing cost of single-junction organic solar cells was187（?）/m2,most of which was material cost（132（?）/m2）.The minimum sustainable price was 3.03（?）/Wp;and the levelized cost of energy was 0.324（?）/k Wh.The analysis results showed that reducing manufacturing costs,increasing production efficiency,improving photoelectric conversion efficiency,and improving stability are the future directions for reducing levelized cost of energy of organic solar power generation modules and moving towards commercial applications. |
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