Improve the performance of the quantum dot sensitized ZnO nanotube solar cells with inserting ZnS-MnS composites layers

• Published in: Journal of alloys and compounds 2019-05, Vol.787, p.751-758
• Main Authors: Shen, Wenjian, Zhang, Jing, Wang, Shiyu, Du, Heping, Tang, Yiwen
• Format: Article
• Language: English
• Subjects: Cadmium sulfide; Chemical bath deposition; Composite materials; Electrolytic cells; Electromagnetic absorption; Energy conversion efficiency; Holes (electron deficiencies); Interface passivation layer; Ion exchange; Luminous intensity; Nanotubes; Organic chemistry; Passivity; Performance enhancement; Photovoltaic cells; Quantum dots; Quantum dots-sensitized solar cells; Solar cells; Zinc oxide; Zinc sulfide; ZnS-MnS composites
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.02.108

Interface passivation layer deposited onto photoanodes has been proven to be an available way to suppress charge recombination and enhance the power conversion efficiency in quantum dot-sensitized solar cells. In this work, the ZnS-MnS composites layers inserted in ZnO/CdS nanotubes photoanodes interface is firstly fabricated via ion-exchange and chemical bath deposition methods, simultaneously. By inserting the ZnS-MnS composites, electron back transfer is efficiently hindered. In addition, the uniform ZnS-MnS layer effectively blocks the direct contact between the polysulfide electrolyte and ZnO nanotubes, which inhabits the recombination of electron-hole pairs occurred at the interface. Besides, the MnS layer is in favour of the CdS quantum dots in higher load, profiting the light absorption intensity in the visible light region. Thus ZnO/ZnS-MnS/CdS nanotubes quantum dot-sensitized solar cells have efficiency of 3.62%, which is much higher than that of the solar cell with ZnS passivation layer (2.33%). This work demonstrates that constructing ZnS-MnS interface passivation layer with a proper band gap structure is a promising approach to enhance the performance of quantum dot-sensitized solar cells. •The ZnS-MnS composites passivation layer is fabricated between ZnO nanotube and CdS.•The presence of MnS is in favour of the loading of CdS quantum dots on the nanotube.•ZnS-MnS passivation layer inhibits the electron back transfer.•ZnO/ZnS-MnS/CdS QDSSCs exhibits a higher efficiency of 3.62% than ZnO/ZnS/CdS.