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Organic solar cells have continued to be a promising technology for cost-effective and scalable production of renewable energy.[1] With regard to the photoactive materials,small molecule donors possess particular advantages over conjugated polymers such as high purity without batch to batch variations.Driven by these promises,there have been intensive research efforts in small molecule solar cells,with high power conversion efficiencies(PCEs)of over 10%achieved in laboratory.[2] However,due to the relatively poor film forming property and low viscosity of small molecules,it is challenging to realize the fabrication of small molecule solar cells with large scale industrial process[3] such as roll-to-roll processing.Herein,all solution-processed flexible large area small molecule bulk heterojunction solar cells were fabricated via roll-coating technology.[4] Our devices were produced from slot-die coating on a lab-scale mini roll-coater under ambient conditions without the use of spin-coating or vacuum evaporation methods.Four diketopyrrolopyrrole based small molecules(SMs 1-4)were utilized as electron donors with(6,6)-Phenyl-C61-butyric acid methyl ester as acceptor and their photovoltaic performances based on roll-coated devices were investigated.A best PCE of 1.01%,combined with an open circuit voltage of 0.73 V,a short-circuit current density of 3.13 mA cm-2 and a fill factor of 44% were obtained for the device with SM 1,which was the first example reported for efficient roll-coating fabrication of flexible large area small molecule solar cell with PCE exceeding 1%.In addition,roll-coated devices based on SMs 2-4 also showed good performances with PCEs of 0.41%,0.54%,and 0.31%,respectively.Our results prove that small molecules have the potential for the use in the industries for large scale production of efficient organic solar cells.