Self-powered photodetector based on vertical MoO ₃ /MoS ₂ hetero-structure with gate tunable photo-response

Abstract

Tunable photo-response is highly desirable by photodiodes for future optoelectronic applications. As compared to bulk semiconducting materials, the atomically thin two-dimensional (2D) materials may be one of the potential candidates to fabricate such adaptive photodiodes, since they possess not only excellent but also widely tunable optoelectronic properties. The most extensively applied device structure for the 2D materials based photodiodes is the vertically aligned van der Waals heterostructure. However, fabricating the vertical 2D material heterostructures is usually complicated, involving manually stacking multiple 2D material flakes together, which is undesirable for industry applications. In this work, we developed a vertical MoO 3 /MoS 2 heterojunction for photodetection and photovoltaic applications. The device used MoS 2 and its oxidation layer of MoO 3 as the n-and p-type regions, respectively, which can greatly simplify the fabrication process of 2D vertical heterojunctions. Moreover, the device exhibited prominent photo-response with photoresponsivity of 670 mA W −1 , detectivity of 4.77 × 10 10 Jones and power conversion efficiency (PCE) of 3.5% under 0 V bias. The device also presented efficient gate tunability on photocurrent with on/ off ratio of 10 3 . This research provides an alternative way to fabricate 2D materials based vertical heterojunctions for optoelectronic applications with tunable photo-responses.

Solution-Processed Vertical Field-Effect Transistor with Separated Charge Generation and Charge Transport Layers for High-Performance Near-Infrared Photodetection

“…An electric field is produced at a Schottky junction, p–n junction, or p–i–n junction, which facilitates the e–h pair generation and transportation. Several studies have been published on self-powered photodetectors, − which reduce the dependence on the external bias. In our device, the CTL section operates in a self-powered mode ( V SD = 0) at V GS > 0, which further reduces the power consumption.…”

A review of molybdenum disulfide (MoS2) based photodetectors: from ultra-broadband, self-powered to flexible devices

“…The oxygen defects in AlN supported the transportation of photogenerated charge carriers in the hybrid photodetector. Selfpowered photodetectors using a vertical MoO 3 /MoS 2 heterojunction 434 have been fabricated which showed photoresponsivity of 670 mA W À1 and detectivity of 4.77 Â 10 10 Jones under 0 V bias and current I on /I off current ratio of 10 3 . MoS 2(1Àx) Se 2x nanostructured alloys have been used for developing photodetectors by atomic-level tailoring.…”

Solution-processed two-dimensional materials for next-generation photovoltaics

“…109 Based on this strategy, a PV device was fabricated by directly depositing a thin layer of MoO 3 onto MoS 2 , reaching an Z value of 3.5%. 247 Despite these progresses, the application of 2D nonlayered materials in prototypical SCs, including 1st-, 2nd-, and 3rd-generation SCs, has not been established yet, probably due to the difficulties in producing 2D nonlayered materials on a large scale. 109 Therefore, these materials will not be the specific subject of discussion in the present work.…”