Where to find lossless metals?

TL;DR

This study conducts a comprehensive high-throughput search for potential lossless metals in existing inorganic material databases, identifying 381 candidates and proposing future research directions to realize such materials for optoelectronic applications.

Contribution

It is the first large-scale computational screening of inorganic materials to find potential lossless metals with low optical absorption losses.

Findings

381 candidate materials identified with well-isolated partially-filled bands

Most candidates are experimentally insulating due to current DFT limitations

Future directions include exploring conductive oxides and high-pressure synthesis

Abstract

Hypothetical metals having optical absorption losses as low as those of the transparent insulators, if found, could revolutionize optoelectronics. We perform the first high-throughput search for lossless metals among all known inorganic materials in the databases of over 100,000 entries. The 381 candidates are identified -- having well-isolated partially-filled bands -- and are analyzed by defining the figures of merit and classifying their real-space conductive connectivity. The existing experimental evidence of most candidates being insulating, instead of conducting, is due to the limitation of current density functional theory in predicting narrow-band metals that are unstable against magnetism, structural distortion, or electron-electron interactions. We propose future research directions including conductive oxides, intercalating layered materials, and compressing these false-metal candidates under high pressures into eventual lossless metals.