Mitta Sekhar Babu, Ali Fida, Yang Zheng, Moon Inyong, Ahmed Faisal, Yoo Tae Jin, Lee Byoung Hun, Yoo Won Jong
SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea.
Department of Mechanical Engineering, College of Electrical and Mechanical Engineering, National University of Science and Technology, Islamabad 44000, Pakistan.
ACS Appl Mater Interfaces. 2020 May 20;12(20):23261-23271. doi: 10.1021/acsami.9b23450. Epub 2020 May 12.
We investigate the development of gate-modulated tungsten diselenide (WSe)-based lateral pn-homojunctions for visible and near-infrared photodetector applications via an effective oxygen (O) plasma treatment. O plasma acts to induce the p-type WSe for the otherwise n-type WSe by forming a tungsten oxide (WO) layer upon O plasma treatment. The WSe lateral pn-homojunctions displayed an enhanced photoresponse and resulted in open-circuit voltage () and short-circuit current () originating from the pn-junction formed after O plasma treatment. We further notice that the amplitude of the photocurrent can be modulated by different gate biases. The fabricated WSe pn-homojunctions exhibit greater photoresponse with photoresponsivities (ratio of the photocurrent and incident laser power) of 250 and 2000 mA/W, high external quantum efficiency values (%, total number of charge carriers generated for the number of incident photons on photodetectors) of 97 and 420%, and superior detectivity values (magnitude of detector sensitivity) of 7.7 × 10 and 7.2 × 10 Jones upon illumination with visible (520 nm) and near-infrared lasers (852 nm), respectively, at low bias ( = 0 V and = 1 V) at room temperature, demonstrating very high-performance in the IR region superior to the contending two-dimensional material-based photonic devices. These superior optoelectronic properties are attributed to the junctions induced by O plasma doping, which facilitate the effective carrier generation and separation of photocarriers with applied external drain bias upon strong light absorption.
我们通过有效的氧（O）等离子体处理，研究了用于可见光和近红外光电探测器应用的栅极调制二硒化钨（WSe）基横向pn同质结的发展。O等离子体通过在O等离子体处理后形成氧化钨（WO）层，将原本为n型的WSe诱导为p型WSe。WSe横向pn同质结表现出增强的光响应，并产生了源自O等离子体处理后形成的pn结的开路电压（）和短路电流（）。我们还进一步注意到，光电流的幅度可以通过不同的栅极偏置进行调制。所制备的WSe pn同质结在室温下低偏置（ = 0 V和 = 1 V）时，分别用可见光（520 nm）和近红外激光（852 nm）照射时，表现出更高的光响应，其光响应度（光电流与入射激光功率之比）分别为250和2000 mA/W，高外量子效率值（%，光电探测器上产生的电荷载流子总数与入射光子数之比）分别为97和420%，以及优异的探测率值（探测器灵敏度的大小）分别为7.7×10和7.2×10琼斯，在红外区域展现出优于竞争的二维材料基光子器件的非常高性能。这些优异的光电特性归因于O等离子体掺杂诱导的结，其有助于在强光吸收时，通过施加的外部漏极偏置有效地产生载流子并分离光生载流子。
