Two-dimensional (2D) materials may play an important role in future photodetectors due to their natural atom-thin body thickness, unique quantum confinement, and excellent electronic and photoelectric properties. Semimetallic graphene, semiconductor black phosphorus, and transition metal dichalcogenides possess flexible and adjustable bandgaps, which correspond to a wide interaction spectrum ranging from ultraviolet to terahertz. Nevertheless, their absorbance is relatively low, and it is difficult for a single material to cover a wide spectrum. Therefore, the combination of phototransistors based on 2D hybrid structures with other material platforms, such as quantum dots, organic materials, or plasma nanostructures, exhibit ultra-sensitive and broadband optical detection capabilities that cannot be ascribed to the individual constituents of the assembly. This article provides a comprehensive and systematic review of the recent research progress of 2D material photodetectors. First, the fundamental detection mechanism and key metrics of the 2D material photodetectors are introduced. Then, the latest developments in 2D material photodetectors are reviewed based on the strategies of photocurrent enhancement. Finally, a design and implementation principle for high-performance 2D material photodetectors is provided, together with the current challenges and future outlooks.

Due to their persistent photoconductivity, amorphous metal oxide thin films are promising for construction of artificial visual systems. In this work, large-scale, uniformly distributed amorphous InGaO thin films with an adjustable In/Ga ratio and thickness are prepared successfully by a low-cost environmentally friendly and easy-to-handle solution process for constructing artificial visual systems. With the increase of the In/Ga ratio and film thickness, the number of oxygen vacancies increases, along with the increase of post-synaptic current triggered by illumination, benefiting the transition of short-term plasticity to long-term plasticity. With an optimal In/Ga ratio and film thickness, the conductance response difference at a decay of 0 s between the 1st and the 10th views of a 5 × 5 array InGaO thin film transistor is up to 2.88 μA, along with an increase in the I_decay 30s/I_decay 0s ratio from 45.24% to 53.24%, resulting in a high image clarity and non-volatile artificial visual memory. Furthermore, a three-layer artificial vision network is constructed to evaluate the image recognition capability, exhibiting an accuracy of up to 91.32%. All results promise low-cost and easy-to-handle amorphous InGaO thin films for future visual information processing and image recognition.

The V _TH and photo-synaptic behavior of solution-processed amorphous In ₂ O ₃ TFT has been regulated precisely by employing a simple and reversible annealing-illumination method, resulting in a high gain inverter and impressive image denoising ability.

The power consumption is challenging the next-generation electronic and optoelectronic devices. In this Letter, the n-type source-gated transistor (SGT) enabled by CdS nanobelt is investigated in detail, demonstrating the expected low power consumption, along with impressive photodetection performance. The SGT is realized by deliberately introducing the Schottky barrier at the source of the staggered-electrode transistor, exhibiting a small saturated voltage (VSAT) of 0.84 ± 0.21 V and a remarkably low power consumption of 7.56 ± 4.01 nW. Under illumination, the as-constructed SGT also shows a low power consumption of 7.58 nW, which is much lower than that of the most reported phototransistors operating in the saturated region. Moreover, the source-gated phototransistor also shows a high responsivity of 2.54 × 103 A W−1 and a high detectivity of 6.72 × 1012 Jones. All results imply that the as-constructed low-power-consumption source-gated phototransistor promises next-generation high-performance electronic and optoelectronic devices.