Effect of pre-surface treatments on p-Cu2O/Au Schottky junctions

Cuprous oxide (Cu₂O) is a suitable semiconducting material in fabrication for low-cost, eco-friendly semiconductor junction devices. Besides the parameterization of the growth conditions of Cu₂O, formation of metal contacts impact the overall performance of these type of devices. The existence of unavoidable dangling bonds and/or dislocated surface atoms could lead to form imperfect contacts with metals, for example in Cu₂O/Au junction devices. Nevertheless, modification of the Cu₂O thin film surfaces prior to make contacts with Au has shown the capability to alter the junction properties. Here we report that, the application of surface treatments; annealing and/or sulphidation on specifically the electrodeposited p-Cu₂O thin film surfaces, where p-Cu₂O thin films were grown in low cupric ion concentrated acetate bath, has influenced the interfacial properties of particular p-Cu₂O/Au Schottky junctions compared to the untreated p-Cu₂O/Au Schottky junction. This has been well-established by the results of SEM and C-V characterizations of p-Cu₂O/Au Schottky junctions. The subsequent annealing and sulphidation of p-Cu₂O thin film surfaces have lowered the built-in potential value by 121 mV compared to the untreated Schottky junction. This result reveals the possibility of employing surface treatments on electrodeposited Cu₂O thin films in fabrication of high efficient Cu₂O based junction devices.