What is gate tunable?

At the graphene/MoSe2 junction, the positive photocurrent decreases as VSG increases from −1.0 to 0.4 V, and the photocurrent becomes negative at VSG = 0.4 V. The high gate-tunability of the photocurrent is significant for the facile modulation of sensitivity for optical sensors.

Why is graphene so special?

What makes graphene so special is its sp2 hybridisation and very thin atomic thickness (of 0.345 nm). These properties are what enable graphene to break so many records in terms of strength, electricity and heat conduction (as well as many others).

What makes graphene so conductive?

The high electrical conductivity of graphene is due to zero-overlap semimetal with electron and holes as charge carriers. These free electrons present above and below the graphene sheet are called pi (π) electrons and enhance the carbon-to-carbon bonds.

Why is graphene a good conductor of heat?

Graphene is a two-dimensional (2D) material with over 100-fold anisotropy of heat flow between the in-plane and out-of-plane directions. High in-plane thermal conductivity is due to covalent sp2 bonding between carbon atoms, whereas out-of-plane heat flow is limited by weak van der Waals coupling.

Why does graphene have Delocalised electrons?

Within the graphene sheet, each hexagon has two pi-electrons, which are delocalized and enable efficient conduction of electricity. In addition, the holes present in the structure enable phonons to pass through unhindered, which results in high thermal conductivity.

Why is graphite good at conducting electricity?

Each carbon atom is bonded into its layer with three strong covalent bonds. This leaves each atom with a spare electron, which together form a delocalised ‘sea’ of electrons loosely bonding the layers together. These delocalised electrons can all move along together – making graphite a good electrical conductor.