Excitonic devices based on two-dimensional transition metal dichalcogenides van der Waals heterostructures

Abstract

Excitonic devices are an emerging class of technology that utilizes excitons as carriers for encoding, transmitting, and storing information. Van der Waals heterostructures based on transition metal dichalcogenides often exhibit a type II band alignment, which facilitates the generation of interlayer excitons. As a bonded pair of electrons and holes in the separation layer, interlayer excitons offer the chance to investigate exciton transport due to their intrinsic out-of-plane dipole moment and extended exciton lifetime. Furthermore, interlayer excitons can potentially analyze other encoding strategies for information processing beyond the conventional utilization of spin and charge. The review provided valuable insights and recommendations for researchers studying interlayer excitonic devices within van der Waals heterostructures based on transition metal dichalcogenides. Firstly, we provide an overview of the essential attributes of transition metal dichalcogenide materials, focusing on their fundamental properties, excitonic effects, and the distinctive features exhibited by interlayer excitons in van der Waals heterostructures. Subsequently, this discourse emphasizes the recent advancements in interlayer excitonic devices founded on van der Waals heterostructures, with specific attention is given to the utilization of valley electronics for information processing, employing the valley index. In conclusion, this paper examines the potential and current challenges associated with excitonic devices.

Key words： excitonic devices; van der Waals heterostructures; transition metal dichalcogenides; interlayer excitons; valley-Hall effect; optoelectronics

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

This work was supported by the National Key Research and Development Program of China (Grant No. 2022YFB2803900), National Natural Science Foundation of China (Grant Nos. 61704121, 61974075), the Natural Science Foundation of Tianjin City (Grant Nos. 19JCQNJC00700, 22JCZDJC00460), the Scientific Research Project of Tianjin Municipal Education Commission (Grant No. 2019KJ028), Fundamental Research Funds for the Central Universities of Nankai University (Grant No. 22JCZDJC00460). C.Y.J. acknowledges the Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin and the Engineering Research Center of Thin Film Optoelectronics Technology, Ministry of Education of China.

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