Mitigating interfacial recombination enabling efficient semitransparent organic photovoltaics

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-11, Vol.499, p.156475, Article 156475
• Main Authors: Yu, Hailin, Wang, Jiayu, Li, Yuanhao, Liu, Tianyu, Gong, Yufei, Yan, Cenqi, Ran, Qichao, Luo, Qun, Mao, Zupan, Wei, Xin, Meng, Lei, Ma, Changqi, Li, Yongfang, Cheng, Pei
• Format: Article
• Language: English
• Subjects: Charge extraction; Interfacial recombination; Semitransparent organic photovoltaics; Thermal stability
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156475

This study presents a facile approach of depositing 11-mercapto-undecanoic acid (11-MUA) on zinc oxide (ZnO) cathode interlayer in conventional STOPVs, resulting in ZnO/11-MUA/Ag electrode based STOPVs devices with superior optical and electrical correlation multifunctionality, including surface trap density that is 2 orders of magnitude lower than the counterparts based on ZnO/Ag, enhanced power conversion efficiency, significantly improvements in average visible transmittance and long-term thermal stability. [Display omitted] •11-mercapto-undecanoic acid (11-MUA) is used to passivate the defects of ZnO.•11-MUA induces the formation of high-quality ultrathin Ag electrode in semitransparent organic photovoltaics (STOPVs).•The surface trap density of STOPVs is obviously reduced by processing with 11-MUA.•11-MUA simultaneously improves the efficiency and average visible transmittance of STOPVs. Charge recombination at the interface between top electrode and active layer is a substantial current loss pathway in semitransparent organic photovoltaics (STOPVs). Reducing interfacial traps is an effective strategy to mitigate interfacial recombination and promote charge extraction, and thereby improve the power conversion efficiencies (PCEs). Herein, a facile approach of depositing 11-mercapto-undecanoic acid (11-MUA) on zinc oxide (ZnO) cathode interlayer in conventional STOPVs is demonstrated. 11-MUA can form covalent interactions with both ZnO and silver (Ag) and thus can induce the formation of high-quality ultrathin Ag electrode. Compared with that deposited on bare ZnO, the Ag electrode on ZnO/11-MUA shows higher conductivity as well as higher optical transparency. The STOPVs based on ZnO/11-MUA/Ag exhibit 2 orders of magnitude lower surface trap density than the counterparts based on ZnO/Ag. Consequently, 11-MUA simultaneously improves the PCEs from 11.2% to 12.1% and average visible transmittance from 21.6% to 27.0% in the STOPVs. Furthermore, arising from the 11-MUA-modified interface, the thermal stability of STOPVs based on ZnO/11-MUA/Ag is also improved.