Effect of doping on hot-carrier thermal breakdown in perforated graphene metasurfaces

TL;DR

This study investigates how doping levels affect the electrical breakdown behavior in perforated graphene metasurfaces, revealing how electron-hole asymmetry influences device performance and stability.

Contribution

It introduces a detailed analysis of doping effects on hot-carrier breakdown in perforated graphene, highlighting the role of energy barriers and carrier heating in device behavior.

Findings

Doping modifies the positive feedback loop leading to breakdown.

Electron-hole asymmetry significantly impacts current-voltage characteristics.

Framework for optimizing graphene-based electronic and optoelectronic devices.

Abstract

We examine the robustness of the S-shaped current-voltage characteristics associated with hot-carrier-induced electrical breakdown in perforated graphene metasurfaces (PGMs) as a function of doping. The perforation of the graphene layer forms interdigital arrays of graphene microribbons (GMRs) interconnected by graphene nanoribbon (GNR) bridges. These GNR constrictions act as energy barriers for electrons and holes emitted from the GMRs and govern the inter-GMR thermionic current under an applied bias voltage. The doping and the voltage bias establish distinct electron and hole populations in adjacent GMRs. Peltier heating of these carriers within the GMRs increases their effective temperatures, thereby enhancing the inter-GMR current. The resulting positive feedback between carrier heating and current amplification can trigger an electrothermal breakdown, transforming a superlinear current-voltage dependence into an S-shaped characteristic exhibiting negative differential resistance. The degree of electron-hole asymmetry significantly influences this positive feedback and strongly modifies the overall current-voltage response. These results provide a framework for optimizing PGM-based devices employing GMR/GNR architectures, including voltage-controlled fast switches, incandescent emitters, and terahertz bolometric detectors.