Tetra‐Propyl‐Substituted Copper (II) Phthalocyanine as Dopant‐Free Hole Transporting Material for Planar Perovskite Solar Cells (Solar RRL 7∕2018)

Dopant free hole‐transport material containing tetra‐n‐propyl substituted Cu (II) phthalocyanine could form face‐on molecular orientation when spincoated on perovskite, as shown by Zong‐Xiang Xu and co‐workers in article no. 1800050. The as‐fabricated n–i–p planar perovskite solar cells exhibit high power conversion efficiency of 17.8% and long‐term stability of retaining over 94% of their initial efficiency even after storage in humidity about 75% for 800 h without encapsulation.