A powder containing the CuAlO2 phase has been prepared from alpha-LiAlO2 by ion exchange with CuCI at temperatures significantly below 500 degreesC. The diameter of the particles in the powder was in the order of 1 mum. Spectral photovoltage (PV) measurements have been carried out on layers of CuAlO2 particles deposited on glass substrates covered with conductive SnO2:F The sign of the PV corresponds to a p-type semiconductor. The optical band gap and the parameter of the exponential absorption tail of the prepared CuAlO2 amount to 3.54 eV and 40 meV, respectively. (C) 2003 Elsevier B.V. All rights reserved.