Löwen Alexander, Kolluru Naveen, Miao Zhuang, Tückmantel Christian, Kreusel Cedric, Janicke Stefan, Riedl Thomas, Neumaier Daniel
Chair of Smart Sensor Systems and Wuppertal Center for Smart Materials & Systems, University of Wuppertal, Wuppertal 42119, Germany.
Institute of Electronic Devices and Wuppertal Center for Smart Materials & Systems, University of Wuppertal, Wuppertal 42119, Germany.
ACS Appl Mater Interfaces. 2025 Feb 12;17(6):9646-9654. doi: 10.1021/acsami.4c14665. Epub 2025 Feb 2.
The photovoltaic effect offers a simple way for converting light into an electrical signal. Here, we report on the observation of a zero-bias photocurrent in the forward direction of a perovskite-covered metal-insulator-graphene diode (MIG-diode), which is the opposite current direction compared to conventional photovoltaic cells and photodiodes. Photocurrent mapping has been performed to gain insights into the precise position of photocurrent generation, demonstrating that the zero-bias photocurrent is primarily generated at the edges of the active device area. Using the band structure diagram at the device edge and on the device area, the unconventional photocurrent direction could be well explained. In addition, the key parameters for the MIG-perovskite photodiode were extracted experimentally. This includes the power-dependent responsivity of up to 10 mA/W as well as the noise equivalent power of 2.23 × 10 W/√Hz at zero-bias voltage.
光伏效应提供了一种将光转换为电信号的简单方法。在此，我们报告了在钙钛矿覆盖的金属-绝缘体-石墨烯二极管（MIG二极管）正向方向上观察到的零偏压光电流，这与传统光伏电池和光电二极管的电流方向相反。已进行光电流映射以深入了解光电流产生的精确位置，表明零偏压光电流主要在有源器件区域的边缘产生。利用器件边缘和器件区域的能带结构图，可以很好地解释这种非常规的光电流方向。此外，通过实验提取了MIG-钙钛矿光电二极管的关键参数。这包括高达10 mA/W的功率相关响应度以及在零偏压下2.23×10 W/√Hz的噪声等效功率。
