Strategy to Improve the Photovoltaic Performance of Si/CuO Heterojunction via Incorporation of Ta₂O₅ Hopping Layer and MXene as Transparent Electrode

Recently, metal oxide semiconductors, especially copper oxides, have engrossed researchers in the domain of solar cells due to their good optoelectronic properties. The present study reports the development of a heterojunction of CuO and Ta2O5 on pyramidal Si decorated with a thin MXene coating as a transparent conductive electrode. Further, the impact of annealing ambient on the crystalline quality and phase selectivity of the as-deposited CuxOy film has also been investigated. The as-designed Si/Ta2O5/CuO/MXene heterostructure shows improved efficiency as compared to the counter device without a Ta2O5 passivation layer by 109 factors. The superiority of the as-designed heterojunction has been examined in terms of short-circuit current density of −10.5 mA/cm2 and photoconversion efficiency of ∼1.47%, respectively. Therefore, the work emphasizes the importance of the combination of n-Ta2O5 and p-CuO film as the wide- and low-band-gap materials for the future low-cost solar cell compatible with the Si process line technology.