Thin film growth of transparent p-type CuAlO2

Recent results suggest that CuAlO2 may be a p-type transparent conductor, b ut thin film synthesis is difficult because of the complex Cu: Al:O phase d iagram. We report a robust method of making c-axis oriented CuAlO2 thin fil ms. Thin film precursors of CuAlO2 were deposited on sapphire (001) substra tes by radio-frequency sputtering and by pulsed-laser deposition. Subsequen t annealing in air at 1050 degrees C in a closed crucible containing Al2O3 and CuO powders yielded nearly phase-pure, biaxially textured CuAlO2. The f ilms were p-type and transparent with a gap of 3.5 eV. (C) 1999 The Electro chemical Society. S1099-0062(99)08-006-2. All rights reserved.