Graphene lens

[5][6] The application of electric fields transverse to staggered graphene bilayers generates a shift in Fermi energy and an artificial, non-zero band gap (Equation 2,[4] Figure 1).

When the photodetector is exposed to light, excited hot electrons transitioned from the top graphene layer to the bottom, a process promoted by the structural asymmetry of the insulating Ta2O5 barrier.

[4] Utilizing graphene both as a channel for charge transport and light absorption, the photodetectors ably detects the visible to mid-infrared spectrum.

Composed of a series of discs centered about an origin, Fresnel zone plates are manufactured using laser pulses, which embed voids into a reflective lens.

[13] Graphene lenses effectively concentrate light of λ = 850 nm onto a single point 120 μm away from the Fresnel zone plate[13] (Figure 5).

Optoelectronic components such as light-emitting diode (LED) displays, solar cells, and touchscreens require highly transparent materials with low sheet resistance, Rs.

Optical tunability of graphene under strong electric gating
Schematic of double-layer graphene ultra-broadband photodetector (Figure 3)
Graphene's potential relative to other known transparent conductors