Room-Temperature Sputtered Nanocrystalline Nickel Oxide as Hole Transport Layer for p−i−n Perovskite Solar Cells

by Erkan Aydin, Joel Troughton, Michaele De Bastiani, Esma Uğur, Muhammad Sajjad, Areej Alzahrani, Marios Neophytou, Udo Schwingenschlögl, Frédéric Laquai, Derya Baran, Stefaan De Wolf
Article Year: 2018 DOI:


Aydin, E., Troughton, J., De Bastiani, M., Ugur, E., Sajjad, M., Alzahrani, A., Neophytou, M., Schwingenschlögl, U., Laquai, F., Baran, D., De Wolf , S. "Room-Temperature Sputtered Nanocrystalline Nickel Oxide as Hole Transport Layer for p−i−n Perovskite Solar Cells " ACS Applied Energy Materials (2018) 1, 11, 6227-6233​.

Extra Information

This study unveils the potential of the room-temperature processed sputtered-NiOx hole transport layers for the single junction perovskites and perovskite-based tandem solar cells, specifically which has rough bottom cells.


​Nickel oxide (NiOx) is a promising hole transport layer (HTL) for perovskite solar cells (PSCs), as it combines good chemical stability, high broadband optical transparency and a high work function. Excellent power conversion efficiencies (PCE) have already been reported using solution-processed NiOx. However, solution-based techniques usually require high-temperature post-annealing to achieve the required HTL properties of NiOx, which jeopardizes its use for many applications, such as monolithic tandem solar cells. To resolve this issue, we developed room-temperature sputtered NiOx and demonstrated p−i−n PSCs with 17.6% PCE (with negligible hysteresis), which is comparable to the best PSCs using sputtered and annealed NiOx without heteroatom doping. Through detailed characterization and density functional theory (DFT) analysis, we explored the electrical and optical properties of the obtained NiOx films and find that they are strongly linked with the specific defect chemistry of this material. Finally, in view of its use in perovskite/silicon tandem solar cells, we find that direct sputtering on random-pyramid textured silicon wafers results in highly conformal NiOx films.


perovskite solar cells room-temperature processing sputtering nickel oxide conformal deposition large area p-i-n perovskite configuration