Abstract
Quasi two‐dimensional perovskites are promising alternatives to conventional three‐dimensional perovskites because of their high stability and easy tunability. However, controlling the phase distribution according to device architecture remains a major challenge. Here, the manipulation of phase purity and vertical distribution proven by ultrafast transient absorption spectroscopy, and their effect on device characteristics are reported. By adding ethyl acetate as antisolvent, the growth direction of the perovskite film is flipped. CH3NH3Cl and dimethyl sulfoxide are used to slow the growth rate of the crystal, which gives better phase purity. The direction of carrier transfer is tuned accordingly. It is found that solar cell performance is more sensitive to phase purity relative to vertical distribution. These findings are of importance for the applications of quasi‐2D perovskites in different types of devices that require to change phase purity and vertical distribution.
The phase purity and vertical distribution The phase purity and vertical distribution of quasi‐2D perovskite is manipulated for their optoelectronic applications, which require different phase distributions. The direction of carrier transfer is tuned accordingly, proven by transient absorption spectroscopy. Solar cell performance is sensitive to the phase purity and dependent on vertical distribution as well.
