Dye-Sensitized MoS₂ Photodetector with Enhanced Spectral Photoresponse

Abstract

We fabricated dye-sensitized MoS2 photodetectors that utilized a single-layer MoS2 treated with rhodamine 6G (R6G) organic dye molecules (with an optical band gap of 2.38 eV or 521 nm). The proposed photodetector showed an enhanced performance with a broad spectral photoresponse and a high photoresponsivity compared with the properties of the pristine MoS2 photodetectors. The R6G dye molecules deposited onto the MoS2 layer increased the photocurrent by an order of magnitude due to charge transfer of the photoexcited electrons from the R6G molecules to the MoS2 layer. Importantly, the photodetection response extended to the infrared (λ < 980 nm, which corresponded to about half the energy band gap of MoS2), thereby distinguishing the device performance from that of a pristine MoS2 device, in which detection was only possible at wavelengths shorter than the band gap of MoS2, i.e., λ < 681 nm. The resulting device exhibited a maximum photoresponsivity of 1.17 AW(–1), a photodetectivity of 1.5 × 10(7) Jones, and a total effective quantum efficiency (EQE) of 280% at 520 nm. The device design described here presents a significant step toward high-performance 2D nanomaterial-based photodetector.

MoS2–InGaZnO Heterojunction Phototransistors with Broad Spectral Responsivity

“…By contrast, the MoS 2 /a-IGZO heterojunction structure displayed a significant increase in I ph (>10 −6 A) over most of the visible range, demonstrating that a large number of electrons had been generated within the MoS 2 layer by the visible light and were then successfully transferred to the underlying a-IGZO layer, where they contributed to the drain current. A similar mechanism was attributed to phototransistors prepared using rhodamine 6G-treated MoS 2 18 and MoS 2 −graphene hybrid films. 35,36 As the illumination light energy approaches 3 eV (corresponding to an optical band gap of a-IGZO), the I ph of the heterostructured devices approaches the value of the a-IGZO device (Figure 2b).…”

Unconventional solution-phase epitaxial growth of organic-inorganic hybrid perovskite nanocrystals on metal sulfide nanosheets

“…Much effort has thus been made to create TMD-based heterostructures like MoS 2 /graphene [9] and MoS 2 /WS 2 , [10] to improve the efficiency of charge separation/transport. Enhanced light absorption has also been achieved by hybridizing TMDs with noble metal nanoparticles [11], organic dyes [12], silicon (Si) [13], carbon nanotubes [14] and so on.…”

Recent Advances in Electronic and Optoelectronic Devices Based on Two-Dimensional Transition Metal Dichalcogenides

“…In addition, atomically 2D-TMDCs still have physical limitations with light absorption, so the use of an absorption layer (e.g., R6G/PbS/perovskite) was applied on 2D-TMDC photodetectors [226][227][228]. …”