Mixed-Dimensional Anti-ambipolar Phototransistors Based on 1D GaAsSb/2D MoS₂ Heterojunctions

Abstract

The incapability of modulating the photoresponse of assembled heterostructure devices has remained a challenge for the development of optoelectronics with multifunctionality. Here, a gatetunable and anti-ambipolar phototransistor is reported based on 1D GaAsSb nanowire/2D MoS 2 nanoflake mixed-dimensional van der Waals heterojunctions. The resulting heterojunction shows apparently asymmetric control over the anti-ambipolar transfer characteristics, possessing potential to implement electronic functions in logic circuits. Meanwhile, such an anti-ambipolar device allows the synchronous adjustment of band slope and depletion regions by gating in both components, thereby giving rise to the gate-tunability of the photoresponse. Coupled with the synergistic effect of the materials in different dimensionality, the hybrid heterojunction can be readily modulated by the external gate to achieve a highperformance photodetector exhibiting a large on/off current ratio of 4 × 10 4 , fast response of 50 μs, and high detectivity of 1.64 × 10 11 Jones. Due to the formation of type-II band alignment and strong interfacial coupling, a prominent photovoltaic response is explored in the heterojunction as well. Finally, a visible image sensor based on this hybrid device is demonstrated with good imaging capability, suggesting the promising application prospect in future optoelectronic systems.

Type-I PtS2/MoS2 van der Waals heterojunctions with tunable photovoltaic effects and high photosensitivity

“…Most of these the-ories are explained by the existence of recombination centers of different energies and capture cross-sections according to the previous literature reports. 39,[41][42][43] Focusing on this PtS 2 /MoS 2 device, to the best of our knowledge, the superlinear photocurrent and the increasing tendency of responsivity and detectivity (as shown in Fig. 6e) are principally determined by the key component of MoS 2 .…”

One-Dimensional Atomic Chains for Ultimate-Scaled Electronics

“…Also, the ambipolar semiconducting Ta 2 Ni 3 Se 8 ACs, featured with the differential transconductance under positive/negative gate bias, can enable the higher data processing capability in a single device, thus significantly simplifying the circuit design. Based on the same concept, nanoscale ambipolar or anti-ambipolar optoelectronic devices with multifunctionality have been demonstrated most recently. , …”

“…Based on the same concept, nanoscale ambipolar or anti-ambipolar optoelectronic devices with multifunctionality have been demonstrated most recently. 73,74 1D TiS 3 is broadly classified as an n-type semiconductor with a direct bandgap of ∼1 eV. 75 The predicted mobility of TiS 3 is close to ∼10 4 cm 2 along the chain direction, more than an order of magnitude higher than that in the perpendicular direction, featuring an anisotropic carrier transport.…”

Synergistic Effect of Hybrid CdSe Nanobelt/PbI2 Flake Heterojunction Toward Drastic Performance Flexible Photodetectors

“…In order to overcome the constraints of electronics relying on 2D PbI 2 material, mixed-dimensional heterostructures, as a possible solution for future multifunctional platforms, are assumed to be a convenient and effective approach. − Compared to the individual material, a mixed-dimensional heterostructure not only manifests the intrinsic properties of both individual components, as well as displays the extra desirable characteristics as a result of interplay at each component’s interface. − Low cost CdSe, as an important photoelectric chalcogenide of the II–VI group with a direct bandgap of ∼1.74 eV at room temperature, is widely explored in optoelectronics due to its excellent optical and electrical characteristics. − Among other morphologies of CdSe, a distinct 1D nanobelt like morphology with a rectangular shape at the edges has been widely studied in photodetectors. ,− Thus, the present study integrates the distinct properties of the aforementioned sensing materials to fabricate a well performing 1D/2D hybrid heterojunction photodetector. To date, there is no available approach for the fabrication of broadband flexible photodetectors utilizing a single crystalline CdSe nanobelt/2D PbI 2 flake hybrid heterojunction on a cost-effective flexible polyimide tape-based substrate.…”