title: Efficient hysteresis-less bilayer type CH₃NH₃PbI₃ perovskite hybrid solar cells.
abstract: Bilayer type CH3NH3PbI3 (MAPbI3) perovskite hybrid solar cells were fabricated via a one-step spin-coating process by using solubility controlled MAPbI3 solutions of MAPbI3-DMSO (dimethyl sulfoxide) and MAPbI3-DMF (N, N-dimethylformamide)-HI. The best DMSO-bilayer device showed 1.07 ± 0.02 V V(oc) (open-circuit voltage), 20.2 ± 0.1 mA cm(-2) J(sc) (short-circuit current density), 68 ± 2% FF (fill factor), and 15.2 ± 0.3% η (overall power conversion efficiency) under the forward scan direction and 1.07 ± 0.02 V V(oc), 20.4 ± 0.1 mA cm(-2) J(sc), 70 ± 3% FF, and 15.9 ± 0.4% η under the reverse scan direction. The best HI-bilayer device had 1.08 ± 0.02 V V(oc), 20.6 ± 0.1 mA cm(-2) J(sc), 75 ± 1% FF, and 17.2 ± 0.2% η under the forward scan direction and 1.08 ± 0.02 V V(oc), 20.6 ± 0.1 mA cm(-2) J(sc), 76 ± 2% FF, and 17.4 ± 0.3% η under the reverse scan direction. The deviation of average device efficiency (η(avg)) of 20 DMSO samples and 20 HI samples was 14.2 ± 0.95% and 16.2 ± 0.85%, respectively. Therefore, the HI-bilayer devices exhibited better device efficiency and smaller J-V (current density-voltage) hysteresis with respect to the scan direction than the DMSO-bilayer devices due to the reduced recombination and traps by the formation of a purer and larger MAPbI3 perovskite crystalline film.
authors.affiliation: Functional Crystallization Center (ERC), Department of Chemical Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, Korea.
authors.forename: Jin Kyoung
authors.initials: JK
authors.lastname: Park
authors.forename: Jin Hyuck
authors.initials: JH
authors.lastname: Heo
authors.forename: Hye Ji
authors.initials: HJ
authors.lastname: Han
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Lee
authors.forename: Dae Ho
authors.initials: DH
authors.lastname: Song
authors.forename: Myoung Sang
authors.initials: MS
authors.lastname: You
authors.forename: Shi-Joon
authors.initials: SJ
authors.lastname: Sung
authors.forename: Dae-Hwan
authors.initials: DH
authors.lastname: Kim
authors.forename: Sang Hyuk
authors.initials: SH
authors.lastname: Im