A new planar A-D-A structured organic small molecule semiconductor (O-SMS) with dialkyl-thiophene substituted benzodithiophene (BDT) as central electron-rich core flanked by relatively electron-deficient units of [1,2,5]thiadiazolo[3,4-c]pyridine (PTz) and terminated with alkyl-bithiophene as π-conjugated end-caps, BDTDPTz, was designed and synthesized for the application as donor material in organic solar cells (OSCs). BDTDPTz possesses wider absorption spectra with an optical bandgap of 1.65 eV, lower the highest occupied molecular orbital (HOMO) energy level of −5.42 eV and highly crystalline structures in solid films. The OSCs based on BDTDPTz:PC₇₁BM blend film with a lower PC₇₁BM content of 40% demonstrate a power conversion efficiency (PCE) of 6.28% with a relatively higher open-circuit voltage of 0.868 V and short circuit current density of 12.83 mA cm⁻². These results indicate that highly coplanar and crystalline structure of BDTDPTz can effectively reduce the content of fullerene acceptor in the active layer and then enhance the absorption and PCE of the OSCs.

一种新的平面ADA结构的有机小分子半导体（O-SMS），具有二烷基噻吩取代的苯并二噻吩（BDT）作为中心富电子核，侧接[1,2,5]噻二唑[3,4-]的相对缺电子单元设计并合成了c]吡啶（PTz），并以烷基-联噻吩作为π-共轭封端，BDTDPTz终止并用作有机太阳能电池（OSC）的施主材料。BDTDPTz具有较宽的吸收光谱，其光学带隙为1.65 eV，较低的最高占据分子轨道（HOMO）能级为-5.42 eV，并且在固态膜中具有高度结晶的结构。基于BDTDPTz：PC ₇₁ BM混合膜和较低PC ₇₁的OSCBM含量为40％时，功率转换效率（PCE）为6.28％，相对开路电压为0.868 V，短路电流密度为12.83 mA cm ^-2。这些结果表明，BDTDPTz的高度共面和晶体结构可以有效地减少活性层中富勒烯受体的含量，从而增强OSC的吸收和PCE。