| 초록 |
We present a passivation strategy for the perovskite/HTL interface based on potassium acetate (K-Ac). Since K-Ac is soluble in both polar and nonpolar solvent, thus, deposition of K-Ac on top and bottom of perovskite is possible. With this advantage, we report the universality of potassium interfacial passivation at the HTL/perovskite interface applied to various configurations with various range of perovskite bandgap. Regarding the p-i-n configuration, various materials characterizations reveal that a potassium passivation layer underneath perovskite modify perovskite orientations, resulting in a better charge transport and film properties. Furthermore, the potassium passivation layer shift the valence band position of the HTL upward, which result in a better extraction of charges (holes) across the HTL/perovskite interface, thus improving the short-circuit current density (Jsc). The modification of the band alignment at the HTL/perovskite by the potassium interfacial passivation layer is confirm in n-i-p devices with both WBG and CBG perovskites. Compare to reference solar cells without a passivation layer, an increase in Jsc of approximately 1 mA/cm2 was observed in all cases, resulting in power conversion efficiencies of 19.42%, 20.06%, and 22.08% for WBG p-i-n, CBG p-i-n and n-i-p solar cells, respectively, demonstrating the wide applicability of our passivation strategy. |
