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 b inding energies and the magnitude of the 3s multiplet splitting chemical st ates of 2 + and 3 + are assigned to Co and Cr, respectively. FTIR reflectan ce analyses reveal that the surfaces of the pigmented samples contain hydro gen 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 E lsevier Science B.V. All rights reserved.