Tunneling Diode Based on WSe(2) /SnS(2) Heterostructure Incorporating High Detectivity and Responsivity.

van der Waals (vdW) heterostructures based on atomically thin 2D materials have led to a new era in next-generation optoelectronics due to their tailored energy band alignments and ultrathin morphological features, especially in photodetectors. However, these photodetectors often show an inevitable compromise between photodetectivity and photoresponsivity with one high and the other low. Herein, a highly sensitive WSe2 /SnS2 photodiode is constructed on BN thin film by exfoliating each material and manually stacking them. The WSe2 /SnS2 vdW heterostructure shows ultralow dark currents resulting from the depletion region at the junction and high direct tunneling current when illuminated, which is confirmed by the energy band structures and electrical characteristics fitted with direct tunneling. Thus, the distinctive WSe2 /SnS2 vdW heterostructure exhibits both ultrahigh photodetectivity of 1.29 × 1013 Jones (Iph /Idark ratio of ≈106 ) and photoresponsivity of 244 A W-1 at a reverse bias under the illumination of 550 nm light (3.77 mW cm-2 ).

Zhou X ，Hu X ，Zhou S ，Song H ，Zhang Q ，Pi L ，Li L ，Li H ，Lü J ，Zhai T ... -  《-》

Rational Design of WSe(2) /WS(2) /WSe(2) Dual Junction Phototransistor Incorporating High Responsivity and Detectivity.

The excellent semiconducting properties and ultrathin morphological characteristics allow van der Waals (vdW) heterostructures based on 2D materials to be promising channel materials for the next-generation optoelectronic devices, especially in photodetectors. Although various 2D heterostructure-based photodetectors have been developed, the unavoidable trade-off between responsivity and detectivity remains a critical issue for these devices. Here, an ingenious phototransistor based on WSe2 /WS2 /WSe2 dual-vdW heterostructures is constructed, performing both high responsivity and detectivity. In the charge neutrality point (gate voltage of -15 V and bias voltage of 1 V), this device demonstrates a pronounced photosensitivity, accompanying with high detectivity of 1.9 × 1014  Jones, high responsivity of 35.4 A W-1 , and fast rise/fall time of 3.2/2.5 ms at 405 nm with power density of 60 µW cm-2 . Density functional theory calculations, energy band profiles, and optoelectronic characteristics jointly verify that the high performance is ascribed to the distinctive device design, which not only facilitates the separation of photogenerated carriers but also produces a strong photogating effect. As a feasible application, an automotive radar system is demonstrated, proving that the device has considerable potential for application in vehicle intelligent assisted driving.

Luo Z ，Yang M ，Wu D ，Huang Z ，Gao W ，Zhang M ，Zhou Y ，Zhao Y ，Zheng Z ，Li J ... -  《Small Methods》

High photoresponsivity and broadband photodetection with a band-engineered WSe(2)/SnSe(2) heterostructure.

Xue H ，Dai Y ，Kim W ，Wang Y ，Bai X ，Qi M ，Halonen K ，Lipsanen H ，Sun Z ... -  《-》

Toward High-Performance Self-Driven Photodetectors via Multistacking Van der Waals Heterostructures.

Guo S ，Chen Z ，Weller D ，Wang X ，Ding C ，Wang Y ，Liu R ... -  《-》

Graphene/SnS(2) van der Waals Photodetector with High Photoresponsivity and High Photodetectivity for Broadband 365-2240 nm Detection.

Zhao Y ，Tsai TY ，Wu G ，Ó Coileáin C ，Zhao YF ，Zhang D ，Hung KM ，Chang CR ，Wu YR ，Wu HC ... -  《-》