2D Confinement-Driven Epitaxy of Solution-Deposited Cu₂O on GaAs

High Resolution Image Download MS PowerPoint Slide Epitaxial cuprous oxide (Cu 2 O) thin films were deposited from aqueous alkaline solutions within confined microsquares in micropatterned GaAs. Raman spectroscopy and transmission electron microscopy analysis revealed the presence of single-phase Cu 2 O, with no detectable CuO impurity. In contrast to (110) textured polycrystalline Cu 2 O films obtained on unpatterned substrates, monocrystalline Cu 2 O (100) films were obtained within the GaAs microsquares. It was found that a 45° in-plane rotation of the prefabricated microsquares with respect to the [01̅1] GaAs axis promotes Cu 2 O (100) monocrystalline growth by minimizing lattice mismatch and providing optimal substrate/film orientation for growth. The thickness of the Cu 2 O film and the growth rate within the confined squares emerge as dominant parameters affecting crystal quality and controlling photoluminescence emission, as evidenced by formation of point defects, primarily oxygen vacancies.