Modifying a D–A–π–A–D HTM system for higher hole mobility by the meta-substitution strategy to weaken the electron-donating ability of the donor unit: a DFT study

The weak electron-donating ability of the D group in the D–A–π–A–D system lowers λ h and benefits the hole transport of HTMs, while meta -substitution can lower λ h and enhance V ec between dimers simultaneously, thus improving the μ h of HTMs impressively.