p -type electrical conduction in α-AgGaO2 delafossite thin films

Thin films of delafossites of α-AgGaO2 were prepared on α-Al2O3 (0001) and on Si (100) single crystal substrates by pulsed laser deposition. The films have a band gap of 4.12eV and a transparency of more than 50% in the visible region. The electrical conductivity at 300K was 3.2×10−4Scm−1. The positive sign of Seebeck coefficient (+70μVK−1) demonstrated the p-type conduction in the films. Transparent p-n heterojunctions on a glass substrate having a structure glass/ITO∕n-ZnO∕p-AgGaO2 were fabricated. The ratio of forward to reverse current was more than 100 in the range of −2to+2V.