Design, Growth, and Characterization of Crystalline Copper Oxide p-Type Transparent Semiconductive Thin Films with Figures of Merit Suitable for Their Incorporation into Translucent Devices

The development of high-performance p-type transparent conductive oxides (TCOs) is a scientific challenge. Cupric oxide (CuO) and cuprous oxide (Cu2O) are attractive candidates for manufacturing p-type TCOs due to their optoelectronic properties. However, tailoring the copper oxide optical absorption and sheet resistance using scalable and simple synthesis methods is not easy. This work presents a straightforward and highly reproducible methodology based on DC sputtering plus thermal treatments to manufacture copper oxide p-type TCOs with optimal figures of merit. We demonstrate that a low-temperature long-time annealing is capable of changing the conductivity and average transmittance of a determined copper oxide TCO. Our proposed long thermal treatment produces a decrease in the TCO average transmittance from 82 to 67%, but, in return, it generates an increment in the conductivity of 3 orders of magnitude from 2.5 × 10–5 S/cm up to 0.048 S/cm. We estimate that these p-type TCOs could be used to build diverse translucent experimental devices where a p–n heterojunction is required.