Sensitive and Stable Tin–Lead Hybrid Perovskite Photodetectors Enabled by Double‐Sided Surface Passivation for Infrared Upconversion Detection. Issue 26 (17th May 2020)

• Record Type: Journal Article
• Authors: Zhao, Yan; Li, Chenglong; Jiang, Jizhong; Wang, Boming; Shen, Liang
• Is Part Of: Small. Volume 16:Issue 26(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-05-17
• Subjects: double‐sided passivation -- infrared upconversion detection -- perovskite photodetectors -- tin–lead perovskites; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202001534
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Tin(Sn)‐based perovskite is currently considered one of the most promising materials due to extending the absorption spectrum and reducing the use of lead (Pb). However, Sn 2+ is easily oxidized to Sn 4+ in atmosphere, causing more defects and degradation of perovskite materials. Herein, double‐sided interface engineering is proposed, that is, Sn‐Pb perovskite films are sandwiched between the phenethylammonium iodide (PEAI) in both the bottom and top sides. The larger organic cations of PEA+ are arranged into a perovskite surface lattice to form a 2D capping layer, which can effectively prevent the water and oxygen to destroy bulk perovskite. Meanwhile, the PEA+ can also passivate defects of iodide anions at the bottom of perovskite films, which is always present but rarely considered previously. Compared to one sided passivation, Sn‐Pb hybrid perovskite photodetectors contribute a significant enhancement of performance and stability, yielding a broadband response of 300–1050 nm, a low dark current density of 1.25 × 10 –3 mA cm –2 at –0.1 V, fast response speed of 35 ns, and stability beyond 240 h. Furthermore, the Sn‐Pb broadband photodetectors are integrated in an infrared up‐conversion system, converting near‐infrared light into visible light. It is believed that a double‐sided passivation method can provide new strategies to achieving high‐performance perovskite photodetectors. Abstract : The double‐sided surface passivation engineering is the use of phenethylammonium iodide to effectively passivate the top and bottom defects of Sn‐based perovskite films. The increase of grain size, the decrease in density of trap states, and the surface hydrophobicity effectively improve the sensitivity and stability of Sn‐based perovskite photodetectors. Finally, the photodetectors realize the infrared upconversion application.