Multifunctional transparent conductive films <i>via</i> Langmuir–Blodgett assembly of large MXene flakes

The rapid development of information technology has put forward new requirements for multifunctional properties of transparent conductive films (TCFs) beyond their excellent optoelectrical performance. Despite the recent progress in the preparation of multifunctional films composed of Ti₃C₂T_<i>x</i> MXenes, achieving highly uniform single-layer Ti₃C₂T_<i>x</i> MXene films (SLMFs) with continuous and dense conductive pathways to realize multifunctional TCFs (M-TCFs) remains a significant challenge. Here, the Langmuir-Blodgett (LB) technique is employed to assemble large Ti₃C₂T_<i>x</i> MXene (LM) flakes (∼52 μm²) into SLMFs with controlled stacking density and morphology, enabling the fabrication of M-TCFs with high conductivity and transparency simultaneously. The SLMFs assembled from LM flakes (L-SLMFs) not only exhibit balanced optical and electrical properties with a figure of merit of 9.67 (sheet resistance <i>R</i>_s = 318 Ω sq^-1 at transmittance <i>T</i> = 88%) due to the close-packed morphology with significantly reduced inter-flake junctions, but also demonstrate excellent electrothermal conversion capability (105.5 °C within 40 s at 20 V when <i>T</i> = 75%) and remarkable absolute shielding effectiveness (up to 7.86 × 10⁵ dB cm² g^-1 at <i>T</i> = 89%). The LB assembly approach provides a straightforward way to produce high-performance M-TCFs for next-generation electronic devices.