Enhanced photovoltaic performance of perovskite solar cells by Co-doped spinel nickel cobaltite hole transporting layer
Apostolos Ioakeimidis,
Ioannis T. Papadas,
Dimitris Tsikritzis,
Gerasimos S. Armatas,
Stella Kennou,
Stelios A. Choulis
Affiliations
Apostolos Ioakeimidis
Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3603, Cyprus
Ioannis T. Papadas
Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3603, Cyprus
Dimitris Tsikritzis
Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3603, Cyprus
Gerasimos S. Armatas
Department of Materials Science and Technology, University of Crete, Heraklion 71003, Greece
Stella Kennou
Department of Chemical Engineering, University of Patras, 26504 Patras, Greece
Stelios A. Choulis
Molecular Electronics and Photonics Research Unit, Department of Mechanical Engineering and Materials Science and Engineering, Cyprus University of Technology, Limassol 3603, Cyprus
A solution combustion synthesized hole transport layer (HTL) of spinel nickel cobaltite (NiCo2O4) incorporating 3% Cu–2% Li was fabricated using the doctor-blading technique for planar inverted perovskite solar cells (PVSCs). PVSCs incorporating 3% Cu–2% Li-doped NiCo2O4 showed an increase in Jsc and Voc device performance parameters compared to unmodified NiCo2O4, leading to power conversion efficiency (PCE) of 16.5%. X-ray photoelectron spectroscopy measurements revealed the tendency of Cu cations to replace preferably the surface Ni atoms by changing the surface stoichiometry of NiCo2O4, inducing a cathodic polarization. Ultraviolet photoelectron spectroscopy measurements unveiled the increase in the ionization potential by 0.1 eV for a co-doped NiCo2O4 film compared to unmodified NiCo2O4-based HTL. We attribute the enhanced PCE of the inverted PVSCs presented to the improved hole extraction properties of 3% Cu–2% Li NiCo2O4 HTL.
