Solution‐Processed Wafer‐Scale Ag2S Thin Films: Synthesis and Excellent Charge Transport Properties. (15th April 2022)

• Record Type: Journal Article
• Authors: Wang, Junren; Fu, Shuai; Zhang, Heng; Graf, Robert; Halim, Henry; Chen, Shuai; Zheng, Wenhao; Bonn, Mischa; Landfester, Katharina; Riedinger, Andreas; Wang, Hai I.
• Is Part Of: Advanced functional materials. Volume 32:Number 28(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-15
• Subjects: α‐Ag 2S thin films -- band‐like transport -- charge carrier dynamics -- mobility -- solution‐processed synthesis -- THz spectroscopy; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202113147
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Monoclinic α‐Ag2 S is an intriguing member of transition metal sulfides with great potential for all‐inorganic flexible optoelectronics and thermoelectrics. Fabrication of large‐area, high‐quality α‐Ag2 S thin films and understanding their charge transport properties are critical for device operations yet have remained largely unexplored. Here, a novel two‐step, the solution‐processed approach is reported to produce wafer‐sized, highly crystalline α‐Ag2 S thin films. Ultrafast terahertz (THz) conductivity measurements reveal that photogenerated charge carriers undergo efficient band transport, with room‐temperature mobility of ≈ 150 cm 2 V ‐1 s ‐1 and a diffusion length exceeding 500 nm. Furthermore, introducing poly(vinyl alcohol) (PVA) as the rigid component into the aqueous silver thiolate precursor enables the synthesis of free‐standing α‐Ag2 S thin films with a mobility of ≈ 35 cm 2 V ‐1 s ‐1, demonstrating their potential for flexible optoelectronics. This study provides a facile synthesis route for high‐quality, large‐area α‐Ag2 S thin films with good charge transport properties, relevant for their integration into optoelectronics and wearable electronics. Abstract : Wafer‐sized α‐Ag2 S thin films on substrates with high mobility of ≈150 cm 2 V −1 s −1 and long diffusion length exceeding 500 nm are produced by a solution‐processed approach. Mechanically flexible, free‐standing α‐Ag2 S films are developed by the addition of poly(vinyl alcohol) into precursors. The resulting free‐standing films possess good carrier mobility of ≈35 cm 2 V −1 s −1, relevant for flexible optoelectronics.