Laminated multilayers of perovskite films with different optical and electronic
characteristics will easily realize high-performance optoelectronic devices
because it is widely demonstrated that differential distribution of film
properties in the vertical direction of devices plays particularly important
roles in device performance. However, the existing laminated perovskite films
are hardly prepared by a solution process because there is no solvent with
sufficient selectivity of solubility for different perovskite materials. Here, it is
demonstrated that aniline (AN) has a largely different solubility toward the
perovskite MAPbI3 and the MAPbI3 blend with an additive of hydrochloride
diethylammonium chloride. By using AN as the solvent in the perovskite
precursor solution, two laminated perovskite layers with different crystal
size and optical and electrical characteristics are achieved. Inverted perovskite
solar cells with the laminated films as active layers achieve an averaged power
conversion efficiency of 20.65% originating from the high VOC 1.112 V and fill
factor of 80.8%. The devices maintain 98% efficiency after 400 h under 65%
RH. This work provides a very simple and feasible method for production of
laminated perovskite films to achieve high-performance perovskite solar cells.