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During last 18 years,organic solar cells based on conjugated polymer( or small molecule) donors and fullerene acceptors have been advancing rapidly with PCE already exceeding 12%.PCE enhancement benefits from the development of novel photoactive materials,new device structures,and new interfacial materials.In this talk,I will report recent progress in my labs on the development of fullerene materials for OPV application as follows: ( 1 ) Fullerene absorption was pushed into near-IR region by conjugately fusing oligothiophenes into fullerene.The 1.05 eV bandgap for OC60-5T is among the lowest bandgaps for a fullerene- related π-system.(2) Mono- and bisadducts of thieno-o-quinodimethane with C60 ( TOQC) were prepared.The pristine TOQC bisadduct( bis-TOQC) shows much higher performance than the side chain-substituted TOQC bisadducts in polymer solar cells,while the situation is inverse for TOQC mono-adducts.5.1% PCE was obtained from bis-TOQC: P3 HT solar cells.( 3 ) Two novel 56-π-electron fullerenes,o-quinodimethane-methano [60 ] fullerene ( OQMF ) and thieno-o-quinodimethane-methano [ 60 ] fullerene ( TOQMF ),were prepared by Diels-Alder reaction.5.74% and 5.51% PCEs were achieved for OQMF/P3HT and TOQMF/P3HT solar cells,respectively.(4 ) A 54-π-electron fullerene acceptor.bis-thieno-o-quinodimethane-methano [ 60 ] fullerene ( bis-TOQMF),was developed.The highest 4.56% PCE was achieved for 54-π-electron fullerene solar cells to date.The electron mobility of bis-TOQMF is 10 times higher than that of tris-TOQC.Bis- TOQMF/P3HT solar cells show higher thermal stability than PC61 BM/P3HT solar cells.(5) A new class of thermo-cleavable fullerenes was facilely prepared through one-step Bingel reaction from C60.At high temperature,the tertiary alkyl ester groups of the three compounds undergo thermo-cleavage processes to produce insoluble methano [ 60 ] fullerene-carboxylic acids ( MCAs).MCA buffer layer can significantly enhance JSC and FF of inverted solar cells.(6) A crosslinker,octane-l,8-diyl bis ( 1,4-dihydrobenzo [ d] [ 1,2 ] oxathiine-6-carboxylate 3-oxide) ( OBOCO),was designed to crosslink PC61BM via a heat-triggered Diels- Alder reaction to suppress the aggregation tendency of fullerene molecules.thus helping to stabilize the ideal morphology and to improve device stability.