Efficient Thermally Evaporated γ‐CsPbI3 Perovskite Solar Cells. Issue 29 (10th June 2021)

• Record Type: Journal Article
• Authors: Zhang, Zongbao; Ji, Ran; Kroll, Martin; Hofstetter, Yvonne J.; Jia, Xiangkun; Becker‐Koch, David; Paulus, Fabian; Löffler, Markus; Nehm, Frederik; Leo, Karl; Vaynzof, Yana
• Is Part Of: Advanced energy materials. Volume 11:Issue 29(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-10
• Subjects: PEAI -- perovskite -- solar cells -- thermal evaporation -- γ‐CsPbI 3; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202100299
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Thin‐film deposition by thermal evaporation offers many advantages, yet in the field of perovskite photovoltaics solution‐processed devices significantly outperform those fabricated by thermal evaporation. Here, high‐quality γ‐CsPbI3 perovskite layers by coevaporation of PbI2 and CsI with a small amount of phenylethylammonium iodide (PEAI) are deposited. It is demonstrated that the addition of PEAI into the perovskite layers leads to a preferred crystal orientation and a far improved microstructure, with columnar domains that protrude throughout the film's thickness. This is accompanied by a reduced density of defects as evidenced by the increase in photoluminescence and decrease in Urbach energy as compared to reference CsPbI3 films. Photovoltaic devices based on the PEAI containing perovskite layers reach up to 15% in power conversion efficiency, thus surpassing not only the performance of reference CsPbI3 devices, but also that of most solution‐processed PEAI containing inorganic CsPbX3 (X = Cl, Br, I) perovskite solar cells. Importantly, encapsulated thermally evaporated perovskite devices maintain their performance for over 215 days, demonstrating the stabilizing effect of PEAI on thermally evaporated CsPbI3 . Abstract : In this work, thermally deposited γ‐CsPbI3 perovskite solar cells that include small amounts of coevaporated phenylethylammonium iodine (PEAI) are demonstrated. The incorporation of PEAI leads to highly oriented γ‐CsPbI3 films with improved microstructure and reduced density of defects. The resulting solar cells reach an efficiency of 15% and exhibit an excellent shelf‐storage, thermal and photostability.