Luminescence Properties of Epitaxial Cu[sub.2]O Thin Films Electrodeposited on Metallic Substrates and Cu[sub.2]O Single Crystals

• Published in: Materials Vol. 16; no. 12
• Main Authors: Trinkler, Laima, Dai, Dajin, Chang, Liuwen, Chou, Mitch Ming-Chi, Wu, Tzu-Ying, Gabrusenoks, Jevgenijs, Nilova, Dace, Ruska, Rihards, Berzina, Baiba, Nedzinskas, Ramunas
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-06-2023
• Subjects: Detectors; Dielectric films; Epitaxy; Thin films
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16124349

The luminescent properties of epitaxial Cu[sub.2]O thin films were studied in 10–300 K temperature range and compared with the luminescent properties of Cu[sub.2]O single crystals. Cu[sub.2]O thin films were deposited epitaxially via the electrodeposition method on either Cu or Ag substrates at different processing parameters, which determined the epitaxial orientation relationships. Cu[sub.2]O (100) and (111) single crystal samples were cut from a crystal rod grown using the floating zone method. Luminescence spectra of thin films contain the same emission bands as single crystals around 720, 810 and 910 nm, characterizing V[sub.O] [sup.2+], V[sub.O] [sup.+] and V[sub.Cu] defects, correspondingly. Additional emission bands, whose origin is under discussion, are observed around 650–680 nm, while the exciton features are negligibly small. The relative mutual contribution of the emission bands varies depending on the thin film sample. The existence of the domains of crystallites with different orientations determines the polarization of luminescence. The PL of both Cu[sub.2]O thin films and single crystals is characterized by negative thermal quenching in the low-temperature region; the reason of this phenomenon is discussed.