Fabrication and electrical properties of p-CuAlO₂/(n-, p-)Si heterojunctions

CuAlO₂ thin films have been prepared by the chemical solution deposition method on both n-Si and p-Si substrates. X-ray diffraction analysis indicates that the obtained CuAlO₂ films have a single delafossite structure. The current transport properties of the resultant p-CuAlO₂/n-Si and p-CuAlO₂/p-Si heterojunctions are investigated by current–voltage measurements. The p-CuAlO₂/n-Si has a rectifying ratio of ∼35 within the applied voltages of −3.0 to +3.0 V, while the p-CuAlO₂/p-Si shows Schottky diode-like characteristics, dominated in forward bias by the flow of space-charge-limited current.