Fabrication of transparent p–n junction diode based on oxide semiconductors deposited by RF magnetron sputtering

Transparent p–n heterojunction diodes based on oxide semiconductors were fabricated by RF magnetron sputtering on alkali-free glass substrates below 500 °C. 3% Al-doped ZnO (∼400 nm) was deposited as an n-type component, and SrCu2O2 (∼290 nm) as a p-type component. Sn-doped In2O3 (∼190 nm) and 7% V-doped Ni metals (∼13 nm) were deposited as n- and p-type electrodes at room temperature, respectively. XRD pattern revealed the as-deposited n-/p-components were single phases. 3% Al-doped ZnO as an n-type component was deposited under 10% O2 in Ar atmosphere at 400 °C, and showed a conductivity of 0.43 S/cm, carrier density of 1017/cm3 order. SrCu2O2 as a p-type component were deposited under 1% H2 in Ar atmosphere at 500 °C, and showed a conductivity of 0.078 S/cm, carrier density of 1017/cm3 order. The as-deposited p–n heterojunction diode had a total thickness of 895 nm and showed very high optical transparency of about 69% at 550 nm. I–V measurement of the multilayered transparent p–n heterojunction diode exhibited rectifying characteristics, but the turn-on voltage was somewhat obvious depending on the sample preparation condition. A plausible explanation on the rectifying characteristics of the transparent p–n junction diodes will be suggested.