Defect engineering of the electronic transport through cuprous oxide interlayers

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid-State Chemistry

Background:

• Understanding electronic transport in metal-oxide-metal junctions is crucial for developing advanced electronic devices.
• Copper(I) oxide (Cu2O) is a promising semiconductor material for various electronic applications.
• The influence of defects on the electrical properties of Cu2O requires detailed investigation.

Purpose of the Study:

• To investigate the electronic transport properties of Au-(Cu2O)n-Au junctions.
• To explore the impact of varying Cu2O thickness, point defects, and anion substitution on conductance.
• To identify specific defects that enhance or diminish the junction's electrical conductivity.

Main Methods:

• First-principles calculations were employed to model the electronic structure.
• The nonequilibrium Green's function (NEGF) method was utilized to simulate electronic transport.
• Defect formation energies were analyzed to assess defect stability.

Main Results:

• Bulk-like defects generally enhance conductance more than near-interface defects, with exceptions like oxygen vacancies and chlorine substitutional defects.
• Copper deficiency and nitrogen substitution exhibit similar transmission behaviors, as do chlorine substitution and nitrogen interstitials in thicker junctions.
• Nitrogen and chlorine doping were found to enhance conductance, consistent with experimental findings.
• A Frenkel defect (oxygen interstitial and substitutional) remarkably increases conductance.
• Copper vacancies are identified as particularly stable defects.

Conclusions:

• Defect type and location critically determine the electronic transport characteristics of Cu2O-based junctions.
• Specific dopants (N, Cl) and defect configurations (Frenkel defects) can significantly improve junction conductance.
• The stability of copper vacancies suggests their prevalence and potential impact on device performance.