Chemical deposition of Cu2O films with ultra-low resistivity: correlation with the defect landscape

Cuprous oxide (Cu2O) is a promising p-type semiconductor material for many applications. So far, the lowest resistivity values are obtained for films deposited by physical methods and/or at high temperatures (similar to 1000 degrees C), limiting their mass integration. Here, Cu2O thin films with ultra-low resistivity values of 0.4 0.cm were deposited at only 260 degrees C by atmospheric pressure spatial atomic layer deposition, a scalable chemical approach. The carrier concentration (7.10(14)-2.10(18) cm(-3)), mobility (1-86 cm(2)/V.$), and optical band-gap (2.2-2.48 eV) are easily tuned by adjusting the fraction of oxygen used during deposition. The properties of the films are correlated to the defect landscape, as revealed by a combination of techniques (positron annihilation spectroscopy (PAS), Raman spectroscopy and photoluminescence). Our results reveal the existence of large complex defects and the decrease of the overall defect concentration in the films with increasing oxygen fraction used during deposition.

Automated summary

By using atmospheric pressure spatial atomic layer deposition, Cu2O thin films with ultra-low resistivity values were deposited at low temperatures. The properties of the films, such as carrier concentration, mobility, and optical band-gap, can be easily tuned by adjusting the oxygen fraction used during deposition. The defect landscape of the films is correlated to the overall defect concentration, which decreases with increasing oxygen fraction.