2D/3D
hybrid perovskites have shown great environmental stability
for use as solar cells. Yet insulating organic cation spacers affect
the formation of vertically oriented crystalline grains to hamper
carrier transport. To date, the selection of cation spacers is limited
because crystal growth kinetics should be strictly obeyed. Here, we
adopted a mobile-media-assisted method to fabricate highly oriented
2D/3D hybrid perovskite films, wherein bulky molecules of (C(CH3)3NH3, TBA) are used as cation spacers.
We found the compositional volatile salt promote the orientation of
perovskite polycrystalline films with various compositions universally.
And we obtained efficient solar cells with a photoelectric conversion
efficiency (PCE) of 17.38% and a certified PCE of 19.30% based on
2D/3D hybrid perovskites an overall stoichiometry matching n = 10 and 20, respectively, which are one of the highest
efficiencies among all 2D/3D hybrid perovskite based solar cells so
far. These findings largely broaden the selection category of bulky
cations and promote further exploration of more functional organic
cations.