A Key Laboratory of Microsystems and Microstructures Manufacturing, Ministry of Education, School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China.
Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824, USA.
Sensors (Basel). 2018 May 23;18(6):1668. doi: 10.3390/s18061668.
Black phosphorus (BP), owing to its distinguished properties, has become one of the most competitive candidates for photodetectors. However, there has been little attention paid on photo-response performance of multilayer BP nanoflakes with large layer thickness. In fact, multilayer BP nanoflakes with large layer thickness have greater potential from the fabrication viewpoint as well as due to the physical properties than single or few layer ones. In this report, the thickness-dependence of the intrinsic property of BP photodetectors in the dark was initially investigated. Then the photo-response performance (including responsivity, photo-gain, photo-switching time, noise equivalent power, and specific detectivity) of BP photodetectors with relative thicker thickness was explored under a near-infrared laser beam ( = 830 nm). Our experimental results reveal the impact of BP's thickness on the current intensity of the channel and show degenerated p-type BP is beneficial for larger current intensity. More importantly, the photo-response of our thicker BP photodetectors exhibited a larger responsivity up to 2.42 A/W than the few-layer ones and a fast response photo-switching speed (response time is ~2.5 ms) comparable to thinner BP nanoflakes was obtained, indicating BP nanoflakes with larger layer thickness are also promising for application for ultra-fast and ultra-high near-infrared photodetectors.
黑磷（BP）由于其独特的性质，已成为最有竞争力的光探测器候选材料之一。然而，对于具有较大层厚的多层 BP 纳米片的光响应性能，关注甚少。事实上，从制造角度以及物理性质来看，具有较大层厚的多层 BP 纳米片比单层或少数层的 BP 纳米片更具潜力。在本报告中，首先研究了黑暗中 BP 光电探测器固有特性的厚度依赖性。然后，在近红外激光束（ = 830nm）下，探索了相对较厚厚度的 BP 光电探测器的光响应性能（包括响应率、光增益、光开关时间、等效噪声功率和比探测率）。我们的实验结果揭示了 BP 厚度对沟道电流强度的影响，并表明退化的 p 型 BP 有利于更大的电流强度。更重要的是，我们较厚 BP 光电探测器的光响应表现出高达 2.42A/W 的更大响应率，比少层的光电探测器更高，并且获得了与较薄 BP 纳米片相当的快速光开关速度（响应时间约为 2.5ms），这表明较大层厚的 BP 纳米片也有望应用于超快和超高近红外光探测器。
