Simulation of IR Detector at Communication Window of 1550nm based on Graphene

Abstract

In this paper, photodetection properties of a Graphene-based device at <br />the third telecommunication window have been reported. The structure <br />of the device is a Graphene-silicon Schottky junction which has been <br />simulated in the form of an infrared photodetector. Graphene has specific <br />electrical and optical properties which makes this material a good <br />candidate for optoelectronic applications. Photodetection characteristic <br />of Graphene-silicon Schottky junction is investigated by measuring the <br />(current-voltage) curve at the third telecommunication window under <br />1550nm radiations. The DC electrical characteristic of the device is <br />calculated. The simulated rectifier junction has a potential barrier of <br />0.31eV, the ideality factor of 2.7 and the saturation current of 10-11A. The <br />detector responsivity under 1550nm radiations is measured about <br />20mA/W which is an order of magnitude larger than other Si-based <br />detectors in this wavelength. The internal quantum efficiency (QEin) is <br />calculated about 60% while the external quantum efficiency (QEex) is <br />measured to be 1.6%. A comprehensive theoretical justification is <br />presented based on Fowler theory which allows comparison between the <br />simulation results and the theoretical predictions. For simulating <br />Graphene, a user-defined material is introduced to TCAD-SILVACO <br />software which includes all electrical and optical properties of this novel <br />2D material. Graphene optical properties, specifically at near-IR region<br />(up to 2um wavelength), have been extracted from the real measurement <br />results. Graphene is a Si-compatible material which can provide a <br />sensitive IR detector integrated with other Si-based devices