Pandit Bhishma, Bong Jungwoo, Lee Seongwon, Lee Jungwoo, Pokhrel Sameer, Bae Hagyoul, Kim Ji-Wan, Jeong Yunjo, An Sangmin, Cho Jaehee, Choi Chel-Jong, Ponnusamy Krishna Moorthy, Chandramohan S, Jang Hyeon-Sik, Heo Keun
School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Jeonbuk National University, Jeonju 54896, Republic of Korea.
Department of Electronics Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea.
ACS Appl Mater Interfaces. 2025 Jun 18;17(24):35732-35742. doi: 10.1021/acsami.5c04602. Epub 2025 Jun 6.
The discovery of an intrinsic direct bandgap in single-layer MoS has revealed significant potential for advancements in optoelectronic and photonic applications. This study aims to explore this potential by developing a high-performance Ni/Au metal-semiconductor-metal photodetector on wafer-scale epitaxially grown MoS. The quality of the monolayer MoS film was verified using various techniques, including Raman, photoluminescence (PL), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Results showed a high photoresponse of 2.06 and 0.68 A/W under 350 and 650 nm light illumination, respectively, at a 10 V reverse bias, along with an ultralow dark current measured in picoamps. These results indicate a low noise level and high photo-to-dark current rejection ratios of 5.45 × 10 and 3.41 × 10 under 350 and 650 nm illumination, respectively. The photodetector exhibited a maximum detectivity of 5.1 × 10 cm Hz W at 5 V under 350 nm of UV illumination, and the quantum efficiency surpassed 100% when the reverse bias voltage exceeded 3 V, demonstrating gain manifestation within the device. The dominance of a trap-assisted photoconductive gain mechanism was suggested by the power law exponent and the temporal characteristics observed. UV and visible imaging capabilities were also demonstrated using a "MoS2"-printed shadow mask and a single metal-semiconductor-metal (MSM) photodetector. This study highlights the superior photoimaging capabilities of the MoS MSM photodetector, offering substantial contributions to the field of optoelectronics and suggesting practical applications in photonic devices.
单层二硫化钼（MoS）中本征直接带隙的发现揭示了其在光电子和光子应用方面取得进展的巨大潜力。本研究旨在通过在晶圆级外延生长的二硫化钼上开发高性能的镍/金金属-半导体-金属光电探测器来探索这一潜力。使用包括拉曼光谱、光致发光（PL）、原子力显微镜（AFM）、X射线光电子能谱（XPS）和透射电子显微镜（TEM）在内的各种技术对单层二硫化钼薄膜的质量进行了验证。结果表明，在10V反向偏压下，分别在350nm和650nm光照下的光响应率高达2.06A/W和0.68A/W，同时暗电流测量值为皮安级，极低。这些结果表明，在350nm和650nm光照下，噪声水平较低，光电流与暗电流的抑制比分别为5.45×10和3.41×10。在350nm紫外光照下，该光电探测器在5V时的最大探测率为5.1×10 cm Hz W，当反向偏压超过3V时，量子效率超过100%，表明器件内部存在增益现象。通过幂律指数和观察到的时间特性表明，陷阱辅助光导增益机制起主导作用。还使用“MoS2”印刷的荫罩和单个金属-半导体-金属（MSM）光电探测器展示了紫外和可见光成像能力。本研究突出了二硫化钼MSM光电探测器卓越的光成像能力，为光电子领域做出了重大贡献，并暗示了其在光子器件中的实际应用。
