Ahn Jongtae, Kang Ji-Hoon, Kyhm Jihoon, Choi Hyun Tae, Kim Minju, Ahn Dae-Hwan, Kim Dae-Yeon, Ahn Il-Ho, Park Jong Bae, Park Soohyung, Yi Yeonjin, Song Jin Dong, Park Min-Chul, Im Seongil, Hwang Do Kyung
Center of Opto-Electronic Materials and Devices, Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
Institute of Physics and Applied Physics, Yonsei University, Seoul 03722, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):10858-10866. doi: 10.1021/acsami.9b22288. Epub 2020 Feb 20.
Two-dimensional (2D) van der Waals (vdW) heterostructures herald new opportunities for conducting fundamental studies of new physical/chemical phenomena and developing diverse nanodevice applications. In particular, vdW heterojunction p-n diodes exhibit great potential as high-performance photodetectors, which play a key role in many optoelectronic applications. Here, we report on 2D MoTe/MoS multilayer semivertical vdW heterojunction p-n diodes and their optoelectronic application in self-powered visible-invisible multiband detection and imaging. Our MoTe/MoS p-n diode exhibits an excellent electrical performance with an ideality factor of less than 1.5 and a high rectification (ON/OFF) ratio of more than 10. In addition, the photodiode exhibits broad spectral photodetection capability over the range from violet (405 nm) to near-infrared (1310 nm) wavelengths and a remarkable linear dynamic range of 130 dB within an optical power density range of 10 to 1 W/cm in the photovoltaic mode. Together with these favorable static photoresponses and electrical behaviors, very fast photo- and electrical switching behaviors are clearly observed with negligible changes at modulation frequencies greater than 100 kHz. In particular, inspired by the photoswitching results for periodic red (638 nm) and near-infrared (1310 nm) illumination at 100 kHz, we successfully demonstrate a prototype self-powered visible-invisible multiband image sensor based on the MoTe/MoS p-n photodiode as a pixel. Our findings can pave the way for more advanced developments in optoelectronic systems based on 2D vdW heterostructures.
二维（2D）范德华（vdW）异质结构为开展新物理/化学现象的基础研究以及开发各种纳米器件应用带来了新机遇。特别是，vdW异质结p-n二极管作为高性能光电探测器具有巨大潜力，在许多光电子应用中发挥着关键作用。在此，我们报告二维MoTe/MoS多层半垂直vdW异质结p-n二极管及其在自供电可见-不可见多波段探测与成像中的光电子应用。我们的MoTe/MoS p-n二极管展现出优异的电学性能，理想因子小于1.5，整流（开/关）比高于10。此外，该光电二极管在从紫光（405 nm）到近红外（1310 nm）波长范围内具有宽光谱光电探测能力，在光伏模式下，光功率密度范围为10⁻⁶至1 W/cm²时，线性动态范围高达130 dB。结合这些良好的静态光响应和电学特性，在调制频率大于100 kHz时，能清晰观察到极快的光开关和电开关行为，且变化可忽略不计。特别是，受100 kHz下周期性红光（638 nm）和近红外（1310 nm）光照的光开关结果启发，我们成功展示了一款基于MoTe/MoS p-n光电二极管作为像素的自供电可见-不可见多波段图像传感器原型。我们的研究结果可为基于二维vdW异质结构的光电子系统的更先进发展铺平道路。
