A structure comprising a molybdenum disulfide monolayer on an azobenzene substrate could be used to construct a highly compactable, malleable quasi-two-dimensional transistor powered by light. Credit: atomistic representation of the molybdenum disulfide monolayer with an azobenzene molecule in its trans and cis isomers / Physical review B
Materials that are hybrid constructions (which combine organic and inorganic precursors) and almost two-dimensional (with malleable and highly compactable molecular structures) are increasing in various technological applications, such as the manufacture of smaller and smaller optoelectronic devices.
An article published in Physical Review B describes a study conducted by Diana Meneses Gustin and Luís Cabral, which theoretically explain the unique properties of optics and transport deriving from the interaction between a monolithic of molybdenum disulfide , inorganic substance MoS 2 and a substrate of azobenzene, organic substance C 1
2 H 10 N 2 .
Lighting makes the switch of the molecule azobenzene isomerization and transition from a stable spatial trans configuration to a metastable cis form, producing effects on the electron cloud in the molybdenum disulfide monolayer. These effects, which are reversible, had previously been experimentally studied by Emanuela Margapoti in the postdoctoral research conducted at UFSCar and supported by FAPESP.
Gustin and Cabral developed a model to emulate the process theoretically. "They performed ab initio simulations [computational simulations using only established science] and calculations based on density functional theory [a quantum mechanical method used to investigate the dynamics of many-body systems] and also modeled the transport properties of the disulfide molybdenum monolayer when disturbed by changes in the azobenzene substrate," explained researcher Lopez Richard  the published document does not address the technological applications, the implementation of the effect to construct a two-dimensional transistor activated by light is at the researcher's horizon.
"The nearly two-dimensional structure makes molybdenum bisulphide as attractive as graphene in terms of space reduction and malleability, but it has virtues that potentially make it even better. And 'a semiconductor with electrical conductivity properties similar to graphene and is more versatile optically because it emits light in the range of infrared wavelengths to the visible region, "said Richard.
The hybrid structure of molybdenum disulfide-azobenzene is considered a very promising mat, but a large amount of research and development will be needed to be effectively implemented into useful devices.
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D. Meneses-Gustin et al., Photomodulation of transport in monolayer dichalcogenides, Physical Review B (2018). DOI: 10.1103 / PhysRevB.98.241403