Interface Engineering of Solution-Processed Hybrid Organohalide Perovskite Solar Cells

Author:

Zhang, Shanshan  Stolterfoht, Martin  Armin, Ardalan  Lin, Qianqian  Zu, Fengshuo  Sobus, Jan  Jin, Hui  Koch, Norbert  Meredith, Paul  Burn, Paul L.  Neher, Dieter  

Journal:

ACS APPLIED MATERIALS & INTERFACES

Issue Date:

2018

Abstract(summary):

Engineering the interface between the perovskite absorber and the charge-transporting layers has become an important method for improving the charge extraction and open-circuit voltage (V-OC) of hybrid perovskite solar cells. Conjugated polymers are particularly suited to form the hole-transporting layer, but their hydrophobicity renders it difficult to solution-process the perovskite absorber on top. Herein, oxygen plasma treatment is introduced as a simple means to change the surface energy and work function of hydrophobic polymer interlayers for use as p-contacts in perovskite solar cells. We find that upon oxygen plasma treatment, the hydrophobic surfaces of different prototypical p-type polymers became sufficiently hydrophilic to enable subsequent perovskite junction processing. In addition, the oxygen plasma treatment also increased the ionization potential of the polymer such that it became closer to the valance band energy of the perovskite. It was also found that the oxygen plasma treatment could increase the electrical conductivity of the p-type polymers, facilitating more efficient charge extraction. On the basis of this concept, inverted MAPbI(3) perovskite devices with different oxygen plasma-treated polymers such as P3HT, P3OT, polyTPD, or PTAA were fabricated with power conversion efficiencies of up to 19%.

Page:

21681---21687