Improving the optoelectrical properties of humid stable, hexamined perovskite lattice by phenetylammonium cation additive

The addition of additives into the perovskite system to increase humid stability can reduce the crystallinity and deteriorate the optoelectrical properties of the perovskite. Here, we modify the crystallinity properties of hexamined MAPbI₃ perovskite, a humid-resistant perovskite, by adding penethylammonium iodide (PEAI) molecules to the perovskite system. XRD analysis result suggests that the PEAI causes a significant contraction in perovskite's lattice, which in turn could reconfigures the electronics structure of the perovskite. We found that PEAI succeeded in increasing the grain size from 120 ± 15 nm in pristine perovskite to 180 ± 20 nm in optimum sample (PEAI 1.0) and the compactness of the grain of the film, reducing the trap density from 2.98 × 10²²/cm³ in pristine sample to 1.13 × 10²²/cm³ in optimum sample, and thereby enabling enhanced carrier dynamics at the interface and the bulk structure of the device. We found that the perovskite solar cells device fabricated using this new perovskite system can produce power conversion efficiency as high as 15.75%, which is an increase of as high as 55% than the control device. These findings may become a potential alternative to improve the optoelectrical properties of the perovskite materials.