This paper demonstrates high-efficiency organic near-infrared (NIR) photodetection activity by increasing the symmetry of photoinduced charge density based on planar cyclic donor–acceptor structures. The record-high photosensing capability (gain: 3 × 10⁵ and EQE: 43% at 3 V) is realized under NIR 780 nm illumination upon using the single-component active layer chloroaluminum phthalocyanine (ClAlPc) with planar cyclic intramolecular donor–acceptor structures to create four-fold symmetry of photoinduced charge density. Our in situ measurement using bias-dependent magneto-photocurrent reveals that increasing the symmetry of photoinduced charge density through planar cyclic intramolecular donor–acceptor structures can significantly decrease the electron–hole binding energies, allowing the direct generation of free photogenerated carriers without any heterojunction structures. Particularly, with the four-fold symmetry of photoinduced charge density, the dissociation of electron–hole pairs can be completed at an extremely low critical bias (24.8 mV) in the ClAlPc molecules. Such low critical bias provides the underlying mechanism to directly generate free carriers in the single-component active layer under NIR illumination. Clearly, by using planar cyclic intramolecular donor–acceptor structures, symmetrically arranging photoinduced charge density presents a fundamental strategy to develop high-efficiency NIR sensing capabilities with single-component active layer design in organic molecules.

中文翻译：

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揭示利用单组分光敏层的记录高效有机近红外光电探测器的潜在机制

本文通过增加基于平面环状供体-受体结构的光致电荷密度的对称性，证明了高效的有机近红外（NIR）光检测活性。使用具有平面环状分子内供体-受体结构的单组分活性层氯铝酞菁（ClAlPc），在NIR 780 nm照明下实现了创纪录的高光敏能力（增益：3×10 ⁵和EQE：3 V，43％）。创建光感应电荷密度的四重对称性。我们的原地使用偏倚相关的磁光电流进行的测量显示，通过平面环状分子内供体-受体结构增加光致电荷密度的对称性，可以显着降低电子-空穴结合能，从而允许直接生成自由的光生载流子而没有任何异质结结构。特别是，由于光诱导电荷密度具有四重对称性，因此可以在ClAlPc中以极低的临界偏压（24.8 mV）完成电子-空穴对的解离。分子。如此低的临界偏压提供了在NIR照明下直接在单组分有源层中生成自由载流子的基本机制。显然，通过使用平面环状分子内供体-受体结构，对称排列光诱导的电荷密度提出了一种基本策略，以有机分子中的单组分活性层设计来开发高效的NIR感应功能。