Two p-type small molecules BDTT-TR and TBFT-TR with benzo[1,2-b′:4,5-b′]dithiophene (BDT) and thieno[2,3-f]benzofuran (TBF) as central core units are synthesized and used as donors in all-small-molecule organic solar cells (all-SMOSCs) with a narrow-bandgap small molecule Y6 (2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo [3,4-e]thieno[2″,3’′:4’,5′]thieno[2′,3′: 4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis (5,6- difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) as the acceptor. In comparison to BDTT-TR with centrosymmetric BDT as the central unit, TBFT-TR with asymmetric TBF as the central unit shows red-shifted absorption, higher charge-carrier mobility and better charge pathway in blend films. The power conversion efficiency (PCE) of the all-SMOSCs based on TBFT-TR:Y6 reaches 14.03% with a higher short-circuit current density of 24.59 mA cm⁻² and a higher fill factor of 72.78% compared to the BDTT-TR:Y6 system. The PCE of 14.03% is among the top efficiencies of all-SMOSCs reported in the literature to date.

以苯并[1,2-b'：4,5-b']二噻吩（BDT）和噻吩并[2,3-f]苯并呋喃（TBF）为中心的两个p型小分子BDTT-TR和TBFT-TR单元被合成并用作具有窄带隙小分子Y6（2,2'-（（（2Z，2'Z）-（（12,13--）的全小分子有机太阳能电池（all-SMOSC）双（2-乙基己基）-3,9-二十一烷基-12,13-二氢-[1,2,5]噻二唑[3,4-e] thieno [2″，3''：4'，5'] thieno [2'，3'：4,5]吡咯并[3,2-g] thieno [2'，3'：4,5] thieno [3,2-b]吲哚-2,10-二基）双（亚甲基） ））双（5,6-二氟-3-氧代-2,3-二氢-1 H-茚-2,1-二亚烷基））二烯腈）作为受体。与以中心对称BDT为中心单元的BDTT-TR相比，以不对称TBF为中心单元的TBFT-TR在混合膜中显示红移吸收，更高的电荷载流子迁移率和更好的电荷路径。与BDTT-TR相比，基于TBFT-TR：Y6的全SMOSC的功率转换效率（PCE）达到14.03％，具有更高的短路电流密度24.59 mA cm ^-2和更高的填充因子72.78％ ：Y6系统。PCE为14.03％，是迄今为止文献中报道的所有SMOSC的最高效率之一。