[1] Deng W, Gao K, Yan J, Liang Q, Xie Y, He Z, Wu H, Peng X, Cao Y. Origin of reduced open-circuit voltage in highly efficient smallmolecule-based solar cells upon solvent vapor annealing. ACS Applied Materials & Interfaces, 2018, 10(9): 8141–8147

[2] Liao S H, Jhuo H J, Cheng Y S, Gupta V, Chen S A. A high performance inverted organic solar cell with a low band gap small molecule (p-DTS(FBTTh2)2) using a fullerene derivative-doped zinc oxide nano-film modified with a fullerene-based self-assembled monolayer as the cathode. Journal of Materials Chemistry A, Materials for Energy and Sustainability, 2015, 3(45): 22599–22604

[3] Papamakarios V, Polydorou E, Soultati A, Droseros N, Tsikritzis D, Douvas A M, Palilis L, Fakis M, Kennou S, Argitis P, Vasilopoulou M. Surface modification of ZnO layers via hydrogen plasma treatment for efficient inverted polymer solar cells. ACS Applied Materials & Interfaces, 2016, 8(2): 1194–1205

[4] Singh S P, Kumar C H P, Nagarjuna P, Kandhadi J, Giribabu L, Chandrasekharam M, Biswas S, Sharma G D. Efficient solution processable polymer solar cells using newly designed and synthesized fullerene derivatives. Journal of Physical Chemistry C, 2016, 120(35): 19493–19503

[5] Wu Y, Zou Y, Yang H, Li Y, Li H, Cui C, Li Y. Achieving over 9.8% efficiency in nonfullerene polymer solar cells by environmentally friendly solvent processing. ACS Applied Materials & Interfaces, 2017, 9(42): 37078–37086

[6] Zhao F, Dai S, Wu Y, Zhang Q, Wang J, Jiang L, Ling Q, Wei Z, Ma W, You W, Wang C, Zhan X. Single-junction binary-blend nonfullerene polymer solar cells with 12.1% efficiency. Advanced Materials, 2017, 29(18): 1700144

[7] Zhao W, Li S, Yao H, Zhang S, Zhang Y, Yang B, Hou J. Molecular optimization enables over 13% efficiency in organic solar cells. Journal of the American Chemical Society, 2017, 139(21): 7148–7151

[8] Chakravarthi N, Gunasekar K, Cho W, Long D X, Kim Y H, Song C E, Lee J C, Facchetti A, Song M, Noh Y Y, Jin S H. A simple structured and efficient triazine-based molecule as an interfacial layer for high performance organic electronics. Energy & Environmental Science, 2016, 9(8): 2595–2602

[9] George Z, Xia Y, Sharma A, Lindqvist C, Andersson G, Inganas O, Moons E, Müller C, Andersson M R. Two-in-one: cathode modification and improved solar cell blend stability through addition of modified fullerenes. Journal of Materials Chemistry A, Materials for Energy and Sustainability, 2016, 4(7): 2663–2669

[10] Jeong M, Chen S, Lee S M, Wang Z, Yang Y, Zhang Z G, Zhang C, Xiao M, Li Y, Yang C. Feasible D1-A-D2-A random copolymers for simultaneous high-performance fullerene and nonfullerene solar cells. Advanced Energy Materials, 2018, 8(7): 1702166

[11] Kim T, Younts R, Lee W, Lee S, Gundogdu K, Kim B J. Impact of the photo-induced degradation of electron acceptors on the photophysics, charge transport and device performance of allpolymer and fullerene–polymer solar cells. Journal of Materials Chemistry A, Materials for Energy and Sustainability, 2017, 5(42): 22170–22179

[12] Wang W, Song L, Magerl D, Moseguí González D, Korstgens V, Philipp M, Moulin J F, Müller-Buschbaum P. Influence of solvent additive 1,8-octanedithiol on P3HT:PCBM solar cells. Advanced Functional Materials, 2018, 28(20): 1800209

[13] Cai X, Yuan T, Liu X, Tu G. Self-assembly of 1-pyrenemethanol on ZnO surface toward combined cathode buffer layers for inverted polymer solar cells. ACS Applied Materials & Interfaces, 2017, 9(41): 36082–36089

[14] Lu S, Lin H, Zhang S, Hou J, Choy W C H. A switchable interconnecting layer for high performance tandem organic solar cell. Advanced Energy Materials, 2017, 7(21): 1701164

[15] Zhang F, Shi W, Luo J, Pellet N, Yi C, Li X, Zhao X, Dennis T J S, Li X, Wang S, Xiao Y, Zakeeruddin S M, Bi D, Gratzel M. Isomerpure bis-PCBM-assisted crystal engineering of perovskite solar cells showing excellent efficiency and stability. Advanced Materials, 2017, 29(17): 1606806

[16] Choi H, Mai C K, Kim H B, Jeong J, Song S, Bazan G C, Kim J Y, Heeger A J. Conjugated polyelectrolyte hole transport layer for inverted-type perovskite solar cells. Nature Communications, 2015, 6(1): 7348

[17] Lange I, Reiter S, Patzel M, Zykov A, Nefedov A, Hildebrandt J, Hecht S, Kowarik S, Woll C, Heimel G, Neher D. Tuning the work function of polar zinc oxide surfaces using modified phosphonic acid self-assembled monolayers. Advanced Functional Materials, 2014, 24(44): 7014–7024

[18] Nam S, Seo J, Song M, Kim H, Ree M, Gal Y S, Bradley D D C, Kim Y. Polyacetylene-based polyelectrolyte as a universal interfacial layer for efficient inverted polymer solar cells. Organic Electronics, 2017, 48: 61–67

[19] Cheng Y J, Cao F Y, Lin W C, Chen C H, Hsieh C H. Selfassembled and cross-linked fullerene interlayer on titanium oxide for highly efficient inverted polymer solar cells. Chemistry of Materials, 2011, 23(6): 1512–1518

[20] Seo J H, Gutacker A, Sun Y, Wu H, Huang F, Cao Y, Scherf U, Heeger A J, Bazan G C. Improved high-efficiency organic solar cells via incorporation of a conjugated polyelectrolyte interlayer. Journal of the American Chemical Society, 2011, 133(22): 8416–8419

[21] Zhou D, Xiong S, Chen L, Cheng X, Xu H, Zhou Y, Liu F, Chen Y. A green route to a novel hyperbranched electrolyte interlayer for nonfullerene polymer solar cells with over 11% efficiency. Chemical Communications (Cambridge), 2018, 54(5): 563–566

[22] Chao Y H, Huang Y Y, Chang J Y, Peng S H, Tu W Y, Cheng Y J, Hou J, Hsu C S. A crosslinked fullerene matrix doped with an ionic fullerene as a cathodic buffer layer toward high-performance and thermally stable polymer and organic metallohalide perovskite solar cells. Journal of Materials Chemistry A, Materials for Energy and Sustainability, 2015, 3(40): 20382–20388

[23] Zhang J, Xue R, Xu G, Chen W, Bian G Q, Wei C, Li Y, Li Y. Selfdoping fullerene electrolyte-based electron transport layer for allroom-temperature-processed high-performance flexible polymer solar cells. Advanced Functional Materials, 2018, 28(13): 1705847

[24] Zhao F,Wang Z, Zhang J, Zhu X, Zhang Y, Fang J, Deng D,Wei Z, Li Y, Jiang L, Wang C. Self-doped and crown-ether functionalized fullerene as cathode buffer layer for highly-efficient inverted polymer solar cells. Advanced Energy Materials, 2016, 6(9): 1502120

[25] Cui C, Li Y, Li Y. Fullerene derivatives for the applications as acceptor and cathode buffer layer materials for organic and perovskite solar cells. Advanced Energy Materials, 2017, 7(10): 1601251

[26] Derue L, Dautel O, Tournebize A, Drees M, Pan H, Berthumeyrie S, Pavageau B, Cloutet E, Chambon S, Hirsch L, Rivaton A, Hudhomme P, Facchetti A, Wantz G. Thermal stabilisation of polymer-fullerene bulk heterojunction morphology for efficient photovoltaic solar cells. Advanced Materials, 2014, 26(33): 5831–5838

[27] Duan C, Zhang K, Zhong C, Huang F, Cao Y. Recent advances in water/alcohol-soluble p-conjugated materials: new materials and growing applications in solar cells. Chemical Society Reviews, 2013, 42(23): 9071–9104

[28] Liu J, Ji Y, Liu Y, Xia Z, Han Y, Li Y, Sun B. Doping-free asymmetrical silicon heterocontact achieved by integrating conjugated molecules for high efficient solar cell. Advanced Energy Materials, 2017, 7(19): 1700311

[29] Pal A, Wen L K, Jun C Y, Jeon I, Matsuo Y, Manzhos S. Comparative density functional theory-density functional tight binding study of fullerene derivatives: effects due to fullerene size, addends, and crystallinity on band structure, charge transport and optical properties. Physical Chemistry Chemical Physics, 2017, 19(41): 28330–28343

[30] Zhang Z G, Li H, Qi B, Chi D, Jin Z, Qi Z, Hou J, Li Y, Wang J. Amine group functionalized fullerene derivatives as cathode buffer layers for high performance polymer solar cells. Journal of Materials Chemistry A, Materials for Energy and Sustainability, 2013, 1(34): 9624

[31] Zhang F L, Gadisa A, Inganas O, Svensson M, Andersson M R. Influence of buffer layers on the performance of polymer solar cells. Applied Physics Letters, 2004, 84(19): 3906–3908

[32] Li Y, Zhao Y, Chen Q, Yang YM, Liu Y, Hong Z, Liu Z, Hsieh Y T, Meng L, Li Y, Yang Y. Multifunctional fullerene derivative for interface engineering in perovskite solar cells. Journal of the American Chemical Society, 2015, 137(49): 15540–15547

[33] Liu J, Li J, Liu X, Li F, Tu G. Amphiphilic diblock fullerene derivatives as cathode interfacial layers for organic solar cells. ACS Applied Materials & Interfaces, 2018, 10(3): 2649–2657

[34] Nguyen T L, Lee T H, Gautam B, Park S Y, Gundogdu K, Kim J Y, Woo H Y. Single component organic solar cells based on oligothiophene-fullerene conjugate. Advanced Functional Materials, 2017, 27(39): 1702474

[35] Chen Y, Qin Y,Wu Y, Li C, Yao H, Liang N,Wang X, Li W, Ma W, Hou J. From binary to ternary: improving the external quantum efficiency of small-molecule acceptor-based polymer solar cells with a minute amount of fullerene sensitization. Advanced Energy Materials, 2017, 7(17): 1700328

[36] Hodgkiss J M, Tu G, Albert-Seifried S, Huck W T S, Friend R H. Ion-induced formation of charge-transfer states in conjugated polyelectrolytes. Journal of the American Chemical Society, 2009, 131(25): 8913–8921

[37] Hummelen J C, Knight B W, Lepeq F, Wudl F, Yao J, Wilkins C L. Preparation and characterization of fulleroid and methanofullerene derivatives. Journal of Organic Chemistry, 1995, 60(3): 532–538

[38] Lee H K H, Telford A M, Rohr J A, Wyatt M F, Rice B, Wu J, de Castro Maciel A, Tuladhar S M, Speller E, McGettrick J, Searle J R, Pont S, Watson T, Kirchartz T, Durrant J R, Tsoi W C, Nelson J, Li Z. The role of fullerenes in the environmental stability of polymer: fullerene solar cells. Energy & Environmental Science, 2018, 11(2): 417–428

[39] Yamada M, Ochi R, Yamamoto Y, Okada S, Maeda Y. Transitionmetal- catalyzed divergent functionalization of [60]fullerene with propargylic esters. Organic & Biomolecular Chemistry, 2017, 15(40): 8499–8503