XPS characterization of Co and Cr pigmented copper solar absorbers

XPS is used to characterize the chemical state of Co and Cr on the surfaces of electrochemically pigmented copper plates. Using both the measured 2p binding energies and the magnitude of the 3s multiplet splitting chemical states of 2 + and 3 + are assigned to Co and Cr, respectively. FTIR reflectance analyses reveal that the surfaces of the pigmented samples contain hydrogen bonded OH groups. Optimum solar absorbance and thermal emittance values obtained are alpha = 0.92 and epsilon = 0.17, alpha = 0.96 and epsilon = 0.04 for the Co and Cr pigmented copper collectors, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.