作者:Ji Qi、Liang Ni、Dezhi Yang、Xiaokang Zhou、Wenqiang Qiao、Mao Li、Dongge Ma、Zhi Yuan Wang
DOI:10.1039/c3tc32271h
日期:——
Two donor–acceptor–donor (D–A–D) type low-bandgap small molecules, M1 and M2, with bis(2-thienyl)-N-alkylpyrrole (TPT) as the donor and thieno[3,4-b]thiadiazole (TT) as the acceptor were designed and synthesized. The absorption, transmission, electrochemical, thermal and film properties were studied. The compounds showed panchromatic absorption in the spectral range of 300–1000 nm. Moreover, they also exhibited semi-transparent property in the visible region (400–700 nm). Small molecule photodetectors (SMPDs) based on M1 and M2 were fabricated and studied. For the SMPD with BCP as the hole blocking layer (HBL), a detectivity of 5.0 × 1011 Jones at 800 nm at −0.1 V was obtained, which is among the highest detectivities reported for NIR SMPDs. With a sufficiently thin silver electrode, visibly transparent PDs with an average transmittance of 45% in the visible region were obtained for the first time. The transparent PDs exhibited fairly constant and high detectivity between 1011 and 1012 Jones over a broad spectral range of 300–900 nm. In addition, side chains of the compounds exhibited a great influence on the device performance, which could be assigned to their film absorption coefficient, molecular packing and active layer morphology.
设计并合成了以双(2-噻吩基)-N-烷基吡咯(TPT)为供体、噻吩并[3,4-b]噻二唑(TT)为受体的两种供体-受体-供体(D-A-D)型低带隙小分子 M1 和 M2。研究了这些化合物的吸收、透射、电化学、热和薄膜特性。这些化合物在 300-1000 纳米的光谱范围内具有全色吸收。此外,它们还在可见光区域(400-700 纳米)表现出半透明特性。我们制作并研究了基于 M1 和 M2 的小分子光电探测器(SMPD)。对于以 BCP 作为空穴阻挡层(HBL)的 SMPD,在 -0.1 V 电压下,800 nm 波长处的检测率为 5.0 × 1011 Jones,是已报道的检测率最高的近红外 SMPD 之一。利用足够薄的银电极,首次获得了可见光区平均透射率为 45% 的透明 PD。在 300-900 纳米的宽光谱范围内,这种透明的光致发光器件在 1011-1012 琼斯之间表现出相当稳定和较高的检测率。此外,化合物侧链对器件性能有很大影响,这可能与它们的薄膜吸收系数、分子堆积和活性层形态有关。