Reducing hole transporter use and increasing perovskite solar cell stability with dual-role polystyrene microgel particles

Mu Chen, Muhamad Zulhasif Mokhtar, Eric Whittaker, Qing Lian, Bruce Hamilton, Paul O'Brien, Mingning Zhu, Zhengxing Cui, Saif A. Haque, Brian Saunders

    Research output: Contribution to journalArticlepeer-review


    Perovskite solar cells (PSCs) are a disruptive technology that continues to attract considerable attention due
    to their remarkable and sustained power conversion efficiency increase. Improving PSC stability and reducing
    expensive hole transport material (HTM) usage are two aspects that are gaining increased attention. In
    a new approach, we investigate the ability of insulating polystyrene microgel particles (MGs) to increase PSC
    stability and replace the majority of the HTM phase. MGs are sub-micrometre crosslinked polymer particles
    that swell in a good solvent. The MGs were prepared using a scalable emulsion polymerisation method.
    Mixed HTM/MG dispersions were subsequently spin-coated onto PSCs and formed composite HTM-MG
    layers. The HTMs employed were poly(triaryl amine) (PTAA), poly(3-hexylthiophene) (P3HT) and Spiro-
    MeOTAD (Spiro). The MGs formed mechanically robust composite HTMs with PTAA and P3HT. In contrast,
    Spiro-MG composites contained micro-cracks due the inability of the relatively small Spiro molecules to
    interdigitate. The efficiencies for the PSCs containing PTAA-MG and P3HT-MG decreased by only ∼20%
    compared to control PSCs despite PTAA and P3HT being the minority phases. They occupied only ∼35 vol%
    of the composite HTMs. An unexpected finding from the study was that the MGs dispersed well within the
    PTAA matrix. This morphology aided strong quenching of the CH3NH3PbI3−xClx fluorescence. In addition,
    the open circuit voltages for the PSCs prepared using P3HT-MG increased by ∼170 mV compared to
    control PSCs. To demonstrate their versatility the MGs were also used to encapsulate P3HT-based PSCs.
    Solar cell stability data for the latter as well as those for PSCs containing composite HTM-MG were both far
    superior compared to data measured for a control PSC. Since MGs can reduce conjugated polymer use and
    increase stability they have good potential as dual-role PSC additives.
    Original languageEnglish
    Pages (from-to)10126-10137
    Number of pages12
    Early online date30 Jun 2017
    Publication statusPublished - 2017


    Dive into the research topics of 'Reducing hole transporter use and increasing perovskite solar cell stability with dual-role polystyrene microgel particles'. Together they form a unique fingerprint.

    Cite this