title: Cesium lead iodide solar cells controlled by annealing temperature.
abstract: An inorganic lead halide perovskite film, CsPbI3, used as an absorber in perovskite solar cells (PSCs) was optimized by controlling the annealing temperature and the layer thickness. The CsPbI3layer was synthesized by one-step coating of CsI mixed with PbI2and a HI additive in N,N-dimethylformamide. The annealing temperature of the CsPbI3film was varied from 80 to 120 °C for different durations and the thickness was controlled by changing the spin-coating rpm. After annealing the CsPbI3layer at 100 °C under dark conditions for 10 min, a black phase of CsPbI3was formed and the band gap was 1.69 eV. Most of the yellow spots disappeared, the surface coverage was almost 100%, and the rms roughness was minimized to 3.03 nm after annealing at 100 °C. The power conversion efficiency (PCE) of the CsPbI3based PSC annealed at 100 °C was 4.88%. This high PCE value is attributed to the low yellow phase ratio, high surface coverage, low rms roughness, lower charge transport resistance, and lower charge accumulation. The loss ratio of the PCE of the CH3NH3PbIxCl3-xand CsPbI3based PSCs after keeping in air was 47 and 26%, respectively, indicating that the stability of the CsPbI3based PSC is better than that of the CH3NH3PbIxCl3-xbased PSC. From these results, it is evident that CsPbI3is a potential candidate for solar cell applications.
authors.affiliation: School of Chemical Engineering and Materials Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea. sooyoungkim@cau.ac.kr.
authors.forename: Yu Geun
authors.initials: YG
authors.lastname: Kim
authors.affiliation: School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Kyunggi-do 16419, Republic of Korea. yjkim@skku.edu and Korea Marine Equipment Research Institute #301, Korea Industrial Complex Corp. Gunsan Branch Office R&D Center, 169, Sandannambuk-ro, Gunsan, Jeollabuk-do 573-540, Korea.
authors.forename: Tae-Yoon
authors.initials: TY
authors.lastname: Kim
authors.affiliation: School of Chemical Engineering and Materials Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea. sooyoungkim@cau.ac.kr.
authors.forename: Jeong Hyeon
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Advanced Nano-Surface Research Group, Korea Basic Science Institute, Daejeon 305-333, Republic of Korea.
authors.forename: Kyoung Soon
authors.initials: KS
authors.lastname: Choi
authors.affiliation: School of Mechanical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Kyunggi-do 16419, Republic of Korea. yjkim@skku.edu.
authors.forename: Youn-Jea
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: School of Chemical Engineering and Materials Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea. sooyoungkim@cau.ac.kr.
authors.forename: Soo Young
authors.identifier: http://orcid.org/0000-0002-0685-7991
authors.initials: SY
authors.lastname: Kim