Intrinsic transparent conductors without doping

TL;DR

This paper proposes a novel approach to designing transparent conductors by starting with metallic materials and controlling their intrinsic properties, avoiding doping bottlenecks, and identifies promising materials like Ag3Al22O34.

Contribution

It introduces a new design paradigm for transparent conductors based on intrinsic properties rather than doping, supported by computational material discovery.

Findings

Identified three classes of intrinsic transparent conductors.

Predicted Ag3Al22O34 as a promising intrinsic TC material.

Discovered materials with natural 2D electron gas regions.

Abstract

Transparent conductors (TC's) combine the usually contraindicated properties of electrical conductivity with optical transparency and are generally made by starting with a transparent insulator and making it conductive via heavy doping, an approach that generally faces severe 'doping bottlenecks'. We propose a different idea for TC design-starting with a metallic conductor and designing transparency by control of intrinsic interband transitions and intraband plasmonic frequency. We identify the specific design principles for three such prototypical intrinsic TC classes and then search computationally for materials that satisfy them. Remarkably, one of the intrinsic TC, Ag3Al22O34, is predicted also to be a prototype 3D compounds that manifest natural 2D electron gas (2DEG) regions with very high electron density and conductivity.