Fabrication of all oxide transparent p–n homojunction using bipolar CuInO2 semiconducting oxide with delafossite structure

A transparent homojunction was fabricated with a successive deposition of p- and n-type electronic conductive CuInO2 delafossite-type oxide films by a pulsed laser deposition technique. Each conductivity was realized by doping of Sn4+ ions as donor or Ca2+ ions as acceptor ions. The diode, composed of the p–n homojunction sandwiched by ITO films as anode and cathode, exhibits rectifying characteristics with a turn-on voltage of ∼1.8 V, keeping an optical transmission of 60%–80% in the visible region (its total thickness: 1.8 μm).