The exfoliation and identification of the two-dimensional (2D) single atomic layer of carbon have opened the opportunity to explore graphene and related 2D materials due to their unique properties. 2D materials are regarded as one of the most exciting solutions for next generation electronics and optoelectronics in the technological evolution of semiconductor technology. In this review, we focus on the core concept of “structure-property relationships” to explain the state-of-the-art of 2D materials and summarize the unique electrical and light-matter interaction properties in 2D materials. Based on this, we discuss and analyze the structural properties of 2D materials, such as defects and dopants, the number of layers, composition, phase, strain, and other structural characteristics, which could significantly alter the properties of 2D materials and hence affect the performance of semiconductor devices. In particular, the building blocks principles and potential electronic and optoelectronic applications based on 2D materials are explained and illustrated. Indeed, 2D materials and related heterostructures offer the promise for challenging the existing technologies and providing the chance to have social impact. More efforts are expected to propel this exciting field forward.

Terahertz modulators with high tunability of both intensity and phase are essential for effective control of electromagnetic properties. Due to the underlying physics behind existing approaches there is still a lack of broadband devices able to achieve deep modulation. Here, we demonstrate the effect of tunable Brewster angle controlled by graphene, and develop a highly-tunable solid-state graphene/quartz modulator based on this mechanism. The Brewster angle of the device can be tuned by varying the conductivity of the graphene through an electrical gate. In this way, we achieve near perfect intensity modulation with spectrally flat modulation depth of 99.3 to 99.9 percent and phase tunability of up to 140 degree in the frequency range from 0.5 to 1.6 THz. Different from using electromagnetic resonance effects (for example, metamaterials), this principle ensures that our device can operate in ultra-broadband. Thus it is an effective principle for terahertz modulation.

Two‐dimensional materials are a promising solution for next‐generation electronic and optoelectronic devices due to their unique properties. Owing to the atomic thickness of 2D materials, the light‐matter interaction length in 2D materials is much shorter than that in bulk materials, which limits the performance of optoelectronic devices composed of 2D materials. To improve the light‐matter interactions, optical micro/nano architectures have been introduced into 2D material optoelectronic devices. In this review, we present a concise introduction and discussion of various strategies for the enhancement of light‐matter interaction in 2D materials, namely, the plasmonic effect, waveguide, optical cavity, and reflection architecture. We have outlined the current advances in high‐performance 2D material optoelectronic devices (eg, photodetectors, electro‐optic modulators, light‐emitting diodes, and molecular sensors) assisted by these enhancement strategies. Finally, we have discussed the future challenges and opportunities of micro/nano photonic structure designs in 2D material devices. image