A dopant-free 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT)-based hole transporting layer for highly stable perovskite solar cells with efficiency over 22%

Kaya İ. C., ÖZDEMİR R., USTA H., Sonmezoglu S.

Journal of Materials Chemistry A, vol.10, no.23, pp.12464-12472, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 10 Issue: 23
  • Publication Date: 2022
  • Doi Number: 10.1039/d2ta01541b
  • Journal Name: Journal of Materials Chemistry A
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, MEDLINE, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.12464-12472
  • Kayseri University Affiliated: No

Abstract

© 2022 The Royal Society of ChemistryIn this study, for the first time, n-i-p PSCs were fabricated using dopant-free 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) as the solution-processed hole transporting layer (HTL). The power conversion efficiency (PCE) of the optimized device with the C8-BTBT film that favored edge-on molecular alignment was 22.45% with negligible hysteresis. A thinner dopant-free C8-BTBT HTL effectively protected the perovskite layer from moisture resulting in better shelf-life stability for un-encapsulated PSCs, which maintained >80% of its initial PCE (after a period of 120 days) at a relative humidity level of 40-45%. In addition, the C8-BTBT-based PSCs kept their high performance with no obvious PCE loss at 60 °C for 20 days in the ambient atmosphere and retained 82% of their initial PCE at 85 °C for 10 days. Overall, our findings revealed that a thin solution-processed C8-BTBT HTL plays a critical role not only in hole extraction and transport but also in greatly improving the ambient and thermal stability of n-i-p PSCs.