Multifunctional transparent conductive films via 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 Ti3C2Tx MXenes, achieving highly uniform single-layer Ti3C2Tx 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 Ti3C2Tx MXene (LM) flakes (similar to 52 mu m2) 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 Rs = 318 Omega sq-1 at transmittance T = 88%) due to the close-packed morphology with significantly reduced inter-flake junctions, but also demonstrate excellent electrothermal conversion capability (105.5 degrees C within 40 s at 20 V when T = 75%) and remarkable absolute shielding effectiveness (up to 7.86 x 105 dB cm2 g-1 at T = 89%). The LB assembly approach provides a straightforward way to produce high-performance M-TCFs for next-generation electronic devices.