Diverse field-effect characteristics and negative differential transconductance in a graphene/WS/Au phototransistor with a Ge back gate.

We propose an infrared-sensitive negative differential transconductance (NDT) phototransistor based on a graphene/WS/Au double junction with a SiO/Ge gate. By changing the drain bias, diverse field-effect characteristics can be achieved. Typical p-type and n-type behavior is obtained under negative and positive drain bias, respectively.

Influence of metal-semiconductor junction on the performances of mixed-dimensional MoS/Ge heterostructure avalanche photodetector.

The two-dimensional/three-dimensional van der Waals heterostructures provide novel optoelectronic properties for the next-generation of information devices. Herein, MoS/Ge heterojunction avalanche photodetectors are readily obtained. The device with an Ag electrode at MoS side exhibits more stable rectification characteristics than that with an Au electrode.

High-performance unbiased Ge metal-semiconductor-metal photodetector covered with asymmetric HfSe contact geometries.

A Ge metal-semiconductor-metal photodetector covered with asymmetric contact geometries has been proposed to realize high-performance unbiased photodetection at 1550 nm. At -1 V bias, the responsivity of this device shows a 71% improvement compared to the device without . Moreover, the responsivity and detectivity of this device at zero bias can reach to 71.