Structural and electronic properties of Cu₄O₃ (paramelaconite): the role of native impurities

Abstract

Hybrid density functional theory has been used to study the phase stability and formation of native point defects in Cu4O3. This intermediate copper oxide compound, also known as paramelaconite, was observed to be difficult to synthesize due to stabilization issues between mixed-valence Cu1+ and Cu2+ ions. The stability range of Cu4O3 was investigated and shown to be realized in an extremely narrow region of phase space, with Cu2O and CuO forming readily as competing impurity phases. The origin of p-type conductivity is confirmed to arise from specific intrinsic copper vacancies occurring on the 1+ site. Away from the outlined stability region, the dominant charge carriers become oxygen interstitials, impairing the conductivity by creating deep acceptor states in the electronic band gap region and driving the formation of alternative phases. This study further demonstrates the inadequacy of native defects as a source of n-type conductivity and complements existing experimental findings.

A simple method for the synthesis of copper nanoparticles from metastable intermediates

“…The XR diffractogram peaks at the values 2 θ = 43.30° (Cu-111), 50.43° (Cu-200) and 74.13° (Cu-220), 27 corresponding to the Cu structure synthesized by Step 1 and Step 2. In addition to the characteristic peak of Cu, the XRD pattern contains a weak 2 θ value of Cu 4 O 3 , 28 which indicates that a slight content of copper oxides are also present in the synthesized copper nanoparticles. It is speculated that the oxidation is because copper nanoparticles are extremely easy to be oxidized.…”

Chem4Energy: a consortium of the Royal Society Africa Capacity-Building Initiative

“…Hybrid DFT has been used to study [49] the phase stability and formation of native point defects in Cu 4 O 3 . This intermediate copper oxide compound, also known as paramelaconite, was observed to be difficult to synthesize owing to stabilization issues between mixed-valence Cu 1+ and Cu 2+ ions.…”

Chemical synthesis and super capacitance performance of novel CuO@Cu4O3/rGO/PANI nanocomposite electrode

“…However, the synthesis of Cu 4 O 3 faces significant challenges due to the difficulty in stabilizing both Cu( i ) and Cu( ii ) states simultaneously. 17 This limitation hinders extensive research and practical applications, impeding the realization of its full potential. The electrode materials containing both CuO and Cu 4 O 3 phases can enhance supercapacitor performance.…”