This paper reports on the thermal oxidation of electrodeposited copper microstructures from a 0.2 M H2SO4 + 0.4 M CuSO4 aqueous solution on a copper substrate for selective solar thermal absorbers applications. A study of the morphological properties and crystalline structure of the deposited/annealed layer through SEM-EDS and powder XRD revealed the formation of self-assembled cubic Cu2O microstructures. The copper oxide layer was optically examined by virtue of a spectrometer in the spectral Vis-NIR range. The surface roughness induced by the existence of the globular microstructure has been seen to enhance the absorptance of the material. Around two to three-fold enhancement of optical surface absorption is achieved in the wavelength range of 400-1000 nm versus an air-grown copper oxide. (C) 2014 Elsevier Ltd. All rights reserved.