Understanding the Role of Removable Solid Additives : Selective Interaction Contributes to Vertical Component Distributions

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

23 Scopus Citations
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Author(s)

  • Baobing Fan
  • Wenkai Zhong
  • Huiting Fu
  • Francis R. Lin
  • Reese W.-Y. Wong
  • Ming Liu
  • Chenhui Zhu
  • Cheng Wang
  • Feng Liu

Detail(s)

Original languageEnglish
Article number2302861
Journal / PublicationAdvanced Materials
Volume35
Issue number32
Online published10 May 2023
Publication statusPublished - 10 Aug 2023

Abstract

Sequentially deposited organic solar cells (SD-OSCs) have attracted great attention owing to their ability in achieving more favorable, vertically phase-separated morphology to avoid the accumulation of counter charges at absorber/transporting layer interfaces. However, the processing of SD-OSCs is still quite challenging in preventing the penetration of small-molecule acceptors into the polymer donor layer via erosion or swelling. Herein, solid additives (SAs) with varied electrostatic potential distributions and steric hinderance were introduced into SD-OSCs to investigate the effect of evaporation dynamics and selective interaction on vertical component distribution. Multiple modellings indicate that the π-π interaction dominates the interactions between aromatic SAs and active layer components. Among them, p-dibromobenzene (DBB) shows a stronger interaction with donor while 2-chloronaphthalene (2-CN) interacts more preferably with acceptor. Combining the depth-dependent morphological study aided by multiple X-ray scattering methods, we conclude that the evaporation of SAs can drive the stronger-interaction component upward to the surface, while having minor impact on the overall molecular packing. Ultimately, the 2-CN-treated devices with reduced acceptor concentration at the bottom surface deliver a high power conversion efficiency of 19.2%, demonstrating the effectiveness of applying selective interactions to improve the vertical morphology of OSCs by using SAs with proper structure. © 2023 Wiley-VCH GmbH.

Research Area(s)

  • evaporation dynamics, organic solar cells, selective interactions, solid additives, vertical component distribution

Citation Format(s)

Understanding the Role of Removable Solid Additives: Selective Interaction Contributes to Vertical Component Distributions. / Fan, Baobing; Zhong, Wenkai; Gao, Wei et al.
In: Advanced Materials, Vol. 35, No. 32, 2302861, 10.08.2023.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review