1. Vibronic Exciton–Phonon States in Stack-Engineered van der Waals Heterojunction Photodiodes
- Author
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Barati, Fatemeh, Arp, Trevor B., Su, Shanshan, Lake, Roger K., Aji, Vivek, van Grondelle, Rienk, Rudner, Mark S., Song, Justin C. W., and Gabor, Nathaniel M.
- Abstract
Stack engineering, an atomic-scale metamaterial strategy, enables the design of optical and electronic properties in van der Waals heterostructure devices. Here we reveal the optoelectronic effects of stacking-induced strong coupling between atomic motion and interlayer excitons in WSe2/MoSe2heterojunction photodiodes. To do so, we introduce the photocurrent spectroscopy of a stack-engineered photodiode as a sensitive technique for probing interlayer excitons, enabling access to vibronic states typically found only in molecule-like systems. The vibronic states in our stack are manifest as a palisade of pronounced periodic sidebands in the photocurrent spectrum in frequency windows close to the interlayer exciton resonances and can be shifted “on demand” through the application of a perpendicular electric field via a source-drain bias voltage. The observation of multiple well-resolved sidebands as well as their ability to be shifted by applied voltages vividly demonstrates the emergence of interlayer exciton vibronic structure in a stack-engineered optoelectronic device.
- Published
- 2022
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