Graphene/SnS2 van der Waals Photodetector with High Photoresponsivity and High Photodetectivity for Broadband 365-2240 nm Detection
Graphene/SnS2 van der Waals Photodetector with High Photoresponsivity and High Photodetectivity for Broadband 365-2240 nm Detection
复制标题
具有高光响应度和高光电探测率的石墨烯/SnS2 范德华光电探测器，适用于 365-2240 nm 宽带检测
DOI：
10.1021/acsami.1c11534
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发表时间：
2021
影响因子：
9.5
通讯作者：
Wu Han-Chun
中科院分区：
文献类型：
--
作者：
Yue Zhao;Tsai Tsung-Yin;Wu Gang;Coileain Cormac O.;Zhao Yan-Feng;Zhang Duan;Hung Kuan-Ming;Chang Ching-Ray;Wu Yuh-Renn;Wu Han-Chun
系统地研究了石墨烯/SnS2van der Waals光电探测器的制备及其光电性能。结果表明，干转移石墨烯/SnS2 van der Waals异质结具有从紫外光(365 Nm)到近红外(2.24μm)的宽带传感范围，在470 nm和1064 nm处的响应度和光探测器分别提高了7.7×103A/W和8.9×1013焦耳和1.8×1010焦耳。此外，当探测器被能量大于和小于SnS_2带隙的光子源照射时，分别观察到正和负的光导效应。光响应率(R)与入射功率密度(P)的关系符合经验定律∝Pinβ，正光电导效应符合β>；−1，负光电导效应符合β<；−1。基于Fowler-Nordheim隧道模型和泊松和漂移扩散模拟，我们定量地证明了异质结光电探测器的势垒高度和势垒宽度可以由激光和外加电场通过界面载流子产生的光门效应来控制，从而调节光生载流子的分离和输运。我们的结果可能对设计高性能的范德华异质结光探测器有一定的参考价值。
The fabrication of graphene/SnS2van der Waals photodetectors and their photoelectrical properties are systematically investigated. It was found that a dry transferred graphene/SnS2van der Waals heterostructure had a broadband sensing range from ultraviolet (365 nm) to near-infrared (2.24 μm) and respective improved responsivities and photodetectivities of 7.7 × 103A/W and 8.9 × 1013jones at 470 nm and 2 A/W and 1.8 × 1010jones at 1064 nm. Moreover, positive and negative photoconductance effects were observed when the photodetectors were illuminated by photon sources with energies greater and smaller than the bandgap of SnS2, respectively. The photoresponsivity (R) versus incident power density (P) follows the empirical lawR∝Pinβ, with β > −1 for positive photoconductance effects and β < −1 for negative photoconductance effects. On the basis of the Fowler–Nordheim tunneling model and a Poisson and drift-diffusion simulation, we show quantitatively that the barrier height and barrier width of the heterostructure photodetector could be controlled by a laser and an external electrical field through a photogating effect generated by carriers trapped at the interface, which could be used to tune the separation and transport of photogenerated carriers. Our results may be useful for the design of high performance van der Waals heterojunction photodetectors.