Revealing and reducing the possible recombination loss within TiO2 compact layer by incorporating MgO layer in perovskite solar cells. (15th October 2016)

• Record Type: Journal Article
• Authors: Kulkarni, Ashish; Jena, Ajay K.; Chen, Hsin-Wei; Sanehira, Yoshitaka; Ikegami, Masashi; Miyasaka, Tsutomu
• Is Part Of: Solar energy. Volume 136(2016)
• Page Start: 379
• Page End: 384
• Publication Date: 2016-10-15
• Subjects: TL thin layer -- CL compact layer -- Spiro-OMeTAD 2, 2′, 7, 7′-Tetrakis-(N, N-di-4-methoxyphenylamino)-9, 9′-spirobifluorene -- MgO magnesium oxide -- TiO2 titanium dioxide; Perovskite solar cells -- MgO thin layer -- TiO2 compact layer -- TiO2-MgO bilayer -- FTO/TiO2 interface recombination; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2016.07.019
• Languages: English
• ISSNs: 0038-092X

Abstract

Graphical abstract: Highlights: V oc loss within TiO2 CL and at its interface with FTO is reported. Mechanism for possible recombination loss, at FTO/TiO2 interface is proposed. Device with and without TiO2 compact layer showed same V oc . TiO2 CL does not necessarily help in preventing back transfer of electron. FTO/TiO2 interface engineering can further boost the PCE of perovskite solar cells. Abstract: Here, we report an origin of loss in open circuit voltage ( V oc ) in perovskite solar cells due to the possible trap-assisted recombination within the widely used TiO2 compact layer (CL) and at its interface with FTO substrate. A thin layer (TL) of MgO was employed to investigate the recombination mechanism. MgO in place of TiO2 CL (50–60 nm) enhances V oc of the cell significantly while the MgO layer coated on TiO2 CL (TiO2 -MgO bilayer) does not change the V oc much. In combination with open-circuit voltage decay (OCVD) measurements, we reveal that recombination at FTO/TiO2 interface is a major factor regulating the voltage and efficiency of TiO2 -based perovskite solar cells.