Layer-Dependent Growth of Large Area 2D MoSe₂ Films for Supercapacitor Applications

The large-area growth of two-dimensional molybdenum diselenide (MoSe₂) has garnered significant research attention due to its diverse applications in electronics and energy storage devices. This study explores the continuous synthesis of layered-controlled MoSe₂ films over centimeter-scale areas using the atmospheric pressure chemical vapour deposition (APCVD) method using selenium and molybdenum trioxide as solid precursors. Using optical microscopy, atomic force microscopy, and Raman spectroscopy, we characterized the as-synthesized 2D MoSe₂ films. Remarkably, we achieved large-area MoSe₂ growth on SiO₂/Si substrates across different precursor amounts. However, the surface morphology, thickness, and crystallite size of MoSe₂ domains were significantly influenced by the precursor quantity. Of particular interest, MoSe₂ multilayers synthesized with a higher precursor quantity (20 mg) exhibited enhanced electrochemical performance. Upon illumination, the areal capacitance values experienced a substantial increase, rising from 96 (in the dark) to 115 µF/cm² at a current density of 5 µA/cm².This enhancement can be attributed to light absorption and the generation of photogenerated electron-hole pairs under an applied voltage, resulting in additional charge carriers. These carriers contribute to energy storage and capacitance, potentially allowing for the accumulation of more electrolyte ions at the contact interface. This work highlights the potential for optimizing 2D MoSe₂ layer number for improved energy storage applications.<br/><b>Keywords:</b> CVD, MoSe₂, 2D Materials, AFM, and Supercapacitor