A near‐infrared photodetector with optimized performance is reported using varied thickness (20, 40, 60, and 80 nm) of the active layer comprising chloroaluminium phthalocyanine (ClAlPc) and fullerene (C₇₀) at the ratio of 1:3, and TAPC:10% MoO₃ and BPhen as electron and hole blocking layers, respectively. The experimental results reveal that the photodetector with 80 nm thick active layer provides the best performance at the wavelength of 730 nm achieving a very low dark current density of 1.15 × 10⁻⁹ A cm⁻² and an external quantum efficiency of 74.6% with a responsivity of 0.439 A W⁻¹ at −2 V bias. Additionally, the device exhibits a dramatic high detectivity of 4.14 × 10¹³ cm Hz^1/2 W⁻¹ at 0 V bias. The device exhibits not only a large linear response over a wide optical power range (LDR of 173.0 dB), but also a broad frequency response (778.7 kHz) and rise/fall time of 2.13/0.77 µs (based on trigger pulses at a frequency of 10 kHz) at the applied bias of −2 V. Based on the impedance spectroscopic study and the conventional characterization of electro‐optical properties, the results demonstrate the superiority of this device over other small molecule‐based near‐infrared photodetectors.

中文翻译：

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真空处理的小分子有机光电探测器，具有低暗电流密度和对近红外波长的强响应

据报道，具有变化的厚度（20、40、60和80 nm）的活性层包含1：3的比例的氯铝酞菁（ClAlPc）和富勒烯（C ₇₀）和TAPC，具有最佳性能的近红外光电探测器：10％MoO ₃和BPhen分别作为电子和空穴阻挡层。实验结果表明，具有80 nm厚有源层的光电探测器在730 nm波长下可提供最佳性能，从而实现了1.15×10 ^-9 A cm ^-2的极低暗电流密度和74.6％的外部量子效率。-2 V偏置时的响应度为0.439 AW ^-1。此外，该设备还具有4.14×10 ¹³ cm Hz的惊人高探测率在0 V偏压下为^1/2 W ^-1。该器件不仅在较宽的光功率范围内具有较大的线性响应（LDR为173.0 dB），而且还具有较宽的频率响应（778.7 kHz）和上升/下降时间为2.13 / 0.77 µs（基于某个频率下的触发脉冲）在−2 V的施加偏压下的频率为10 kHz）。基于阻抗光谱研究和常规的电光特性表征，结果证明了该器件优于其他基于小分子的近红外光电探测器。