title: Mechanisms of charge accumulation in the dark operation of perovskite solar cells.
abstract: In this work, a new current peak at forward bias in the dark current-voltage curves has been identified for standard mesoscopic perovskite solar cells. This characteristic peak appears only under some specific conditions, mainly in the reverse scan (RS) direction and when the solar cells were kept for several seconds under short-circuit conditions before starting the RS measurement. This peak disappears when the above experimental conditions are not applied. It is considered that this uncommon diode shape is obtained because shallow and/or deep trap states located at the interface between either perovskite/p-type or perovskite/n-type transport materials are dynamically filled during the RS voltage scan. To corroborate this hypothesis, the response of hole transport materials (HTMs), small molecule spiro-OMeTAD and polymer P3HT, as well as both HTMs with additives, was compared. Also perovskite absorbers such as CH3NH3PbI3 and all-inorganic perovskite based on cesium (CsPbI3) were also analyzed, achieving in all cases similar trends.
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan. teresa@life.kyutech.ac.jp hayase@life.kyutech.ac.jp.
authors.forename: Teresa S
authors.initials: TS
authors.lastname: Ripolles
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan. teresa@life.kyutech.ac.jp hayase@life.kyutech.ac.jp.
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Baranwal
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan. teresa@life.kyutech.ac.jp hayase@life.kyutech.ac.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Nishinaka
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan. teresa@life.kyutech.ac.jp hayase@life.kyutech.ac.jp.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Ogomi
authors.affiliation: Institute of Advance Materials (INAM), Universitat Jaume I, ES-12006 Castelló, Spain. garciag@uji.es.
authors.forename: Germà
authors.initials: G
authors.lastname: Garcia-Belmonte
authors.affiliation: Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan. teresa@life.kyutech.ac.jp hayase@life.kyutech.ac.jp.
authors.forename: Shuzi
authors.initials: S
authors.lastname: Hayase