Novel Spray‐Pyrolysis Deposition of Cuprous Oxide Thin Films

Abstract

Spray pyrolysis of aqueous solutions that include copper(II) acetate, glucose, and 2-propanol was studied for the formation of cuprous oxide (Cu 2 O) thin films on glass substrates. The deposition conditions, based on the phase relations of the films, were investigated in terms of solution concentration and substrate temperature. Also, the formation process was kinetically discussed. The Cu 2 O thin film obtained here was composed of rounded grains ∼50 nm in size with a surface roughness of ∼30 nm. This film was reddish yellow and showed indirect and direct bandgap energies of 1.95 and 2.60 eV, respectively. Furthermore, the film exhibited p-type conduction, with a resistivity of ∼100 ⍀ؒcm.

Growth of ∼5 cm2V−1s−1 mobility, p-type Copper(I) oxide (Cu2O) films by fast atmospheric atomic layer deposition (AALD) at 225°C and below

“…For Cu 2 O in inorganic solar cells, high carrier concentrations of at least 10 16 cm −3 are necessary to achieve the full depletion layer width, thus allowing high open circuit voltage and near theoretical J sc values to be obtained. 13 Cu 2 O thin films can be deposited by several methods including pulsed laser deposition (PLD), 8 sputtering, 14 thermal oxidation, 15 spray pyrolysis 16 and electrochemical deposition. 17 Sputtering appears to be the most successful vacuum method for achieving high mobilities at low temperatures.…”

p-channel thin-film transistors based on spray-coated Cu2O films

“…The SP steps were followed by 12 h anneal at 200 C to improve the quality of the deposited films. It should be noted that this annealing temperature is below the conversion temperature of Cu 2 O to CuO which occurs at around 300 C. 29,30 The crystal structure of Cu 2 O films was determined from X-ray diffraction (XRD) measurements using a PANalytical X'pert MPD diffractometer equipped with an accelerator detector (40 kV, 40 mA). Film surface morphology was investigated using atomic force microscopy (AFM) employing an Agilent 5500 in tapping mode.…”

“…The deposition of thick Cu 2 O films by SP has already been demonstrated by Kosugi and Kaneko. 29 Their approach relies on the use of an aqueous precursor solution of copper(II) acetate monohydrate (Cu(CH 3 COO) 2 (2013) alcohol (IPA) sprayed onto heated substrates. Glucose acts to reduce Cu(II) to Cu(I), which can then form Cu 2 O at a certain range of temperatures while IPA is added to improve the wettability of the solution and the overall film uniformity.…”

Synthesis of a cuprite thin film by oxidation of a Cu metal precursor utilizing ultrasonically generated water vapor

“…To date, various fabrication techniques to obtain a single phase cuprous oxide at low temperatures such as sputtering, pulsed laser deposition, etc. were reported [18][19][20][21][22][23]. However, achieving a reproducible pure cuprite phase of Cu 2 O was still a challenge.…”