Graphene-Si CMOS oscillatorsElectronic supplementary information (ESI) available: Discussions on the shape of the static voltage transfer characteristic of the graphene circuit used in the oscillators, the highest frequency waveforms measured in a parabolic oscillator, and calculated PWM and VCO characteristics of the oscillators. See DOI: 10.1039/C8NR07862A

• Main Authors: Gilardi, Carlo, Pedrinazzi, Paolo, Patel, Kishan Ashokbhai, Anzi, Luca, Luo, Birong, Booth, Timothy J, Bøggild, Peter, Sordan, Roman
• Format: Journal Article
• Language: English
• Published: 21.02.2019
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr07862a

Graphene field-effect transistors (GFETs) offer a possibility of exploiting unique physical properties of graphene in realizing novel electronic circuits. However, graphene circuits often lack the voltage swing and switchability of Si complementary metal-oxide-semiconductor (CMOS) circuits, which are the main building block of modern electronics. Here we introduce graphene in Si CMOS circuits to exploit favorable electronic properties of both technologies and realize a new class of simple oscillators using only a GFET, Si CMOS D latch, and timing RC circuit. The operation of the two types of realized oscillators is based on the ambipolarity of graphene, i.e. , the symmetry of the transfer curve of GFETs around the Dirac point. The ambipolarity of graphene also allowed to turn the oscillators into pulse-width modulators (with a duty cycle ratio ∼1 : 4) and voltage-controlled oscillators (with a frequency ratio ∼1 : 8) without any circuit modifications. The oscillation frequency was in the range from 4 kHz to 4 MHz and limited only by the external circuit connections, rather than components themselves. The demonstrated graphene-Si CMOS hybrid circuits pave the way to the more widespread adoption of graphene in electronics. The ambipolarity of graphene is exploited to realize a new class of electronic oscillators by integrating a graphene field-effect transistor with Si CMOS logic.