Synthesis of Cu2O from CuO thin films: Optical and electrical properties

Abstract

Hole conducting, optically transparent Cu2O thin films on glass substrates have been synthesized by vacuum annealing (5×10−6 mbar at 700 K for 1 hour) of magnetron sputtered (at 300 K) CuO thin films. The Cu2O thin films are p-type and show enhanced properties: grain size (54.7 nm), optical transmission 72% (at 600 nm) and Hall mobility 51 cm2/Vs. The bulk and surface Valence band spectra of Cu2O and CuO thin films are studied by temperature dependent Hall effect and Ultra violet photo electron Spectroscopy (UPS). CuO thin films show a significant band bending downwards (due to higher hole concentration) than Cu2O thin films.

The Phase Evolution and Physical Properties of Binary Copper Oxide Thin Films Prepared by Reactive Magnetron Sputtering

“…Clearly,${\rho }_{{\mathrm{Cu}}_2\mathrm{normalO}}>{\rho }_{{\mathrm{Cu}}_4{\mathrm{O}}_3}>{\rho }_{\mathrm{CuO}}$. The resistivity values of CuO thin films are nearly 2 magnitudes less than those of Cu 2 O and Cu 4 O 3 , which should be attributed to the higher intrinsic carrier density of CuO [28,35,36]. The measured result indicates that the Cu 2 O film with the largest resistivity has the largest band gap and the least Cu valence state, while the CuO film with the least resistivity has the smallest band gap and the largest Cu valence state.…”

Copper‐Doped Chromium Oxide Hole‐Transporting Layer for Perovskite Solar Cells: Interface Engineering and Performance Improvement

“…Metal oxide semiconductors including NiO, MoO 3 , V 2 O 5 , WO 3 , CuO x , and CrO x have been utilized as HTLs in the field of organic solar cells. But there are few formal reports for MoO 3 , V 2 O 5 , CrO x , and WO 3 applied to PSC‐HTL except CuO, Cu 2 O, and NiO, which might be due to that the surface hydrate phase and one of multi valence state oxides in metal oxides could react with the decomposition products of perovskite photoactive layer. This is worth for further in‐depth study to improve the efficiency and stability of PSC.…”

“…Due to its p‐type conductivity with hole mobility exceeding 100 cm 2 V −1 s −1 , low production cost, abundant resource, and low‐lying valence bands matched well with CH 3 NH 3 PbI 3 , Cu 2 O is regarded as one of the most promising materials for application in PSCs. However, they are not the optimal HTLs for inverted‐PSCs because of the narrow band gaps of CuO (1.3–2.0 eV) and Cu 2 O (2.1–2.3 eV) …”

The Inter-play of the Opto-Electrical Properties of Cuprite and Tenorite Semiconductors for Solar Cell Application

“…29.67Ωcm at a temperature of 170°C. The decrease in resistivity with substrate temperature can be attributed to improved crystallinity of the films for all the three different thicknesses [28][29][30]. From equation (10), sheet resistivity, ρ s = R s 10 2 t Ω cm.…”

“…The annealing process could have led to healing of defects created during the oxidation process thereby lowering the resistivity of Cu 2 O. Annealing could have also supported the conversion of the polycrystalline Cu 2 O obtained after the oxidation process to single or nearly single crystal phase of tenorite structure with composition of CuO. [1,2,[30][31][32][33].…”