Improvement of kesterite solar cell performance by solution synthesized MoO3 interfacial layer

In this study, an ultra-thin MoO₃ layer synthesized by a solution-based technique is introduced as a promising interfacial layer to improve the performance of kesterite Cu₂ZnSnSe₄ (CZTSe) solar cell. Solar cells with 10 nm of MoO₃ between Mo rear contact and CZTSe had larger minority carrier life time and open-circuit voltage compared to the reference solar cells. Temperature dependent current density–voltage measurement indicated that the activation energy (E_A) of the main recombination is higher (∼ 837 meV) in solar cells with MoO₃ layer, as compared to conventional solar cells where E_A ∼ 770 meV, indicating reduced interface recombination. A best efficiency of 7.1% was achieved for a SLG/Mo/MoO₃/CZTSe/CdS/TCO solar cell compared to the reference solar cell SLG/Mo/CZTSe/CdS/TCO for which 5.9% efficiency was achieved.