Alternating Nanographene-MoS2 Composite Thin Films Prepared by Pulsed Laser Deposition for Photodetector Applications
摘要
This work introduces an alternating deposition approach for nanographene-MoS2 composite thin films using pulsed laser deposition (PLD) to enhance charge separation and photoresponse efficiency. Nanographene films and nanographene-MoS2 composite thin films were successfully fabricated using PLD via the alternating ablation method. Three samples were prepared: a nanographene film and two nanographene-MoS2 composite films, GM1 with a 2:1 ratio and GM2 with a 1:1 ratio. These ratios correspond to the relative number of laser pulses applied to each target, while the total number of pulses was fixed at 650 for all depositions. Structural, chemical, and morphological analyses were performed using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR), field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and energy-dispersive x-ray spectroscopy (EDS). MoS2 incorporation improved film uniformity, surface roughness, and structural order, while Raman analysis showed a decrease in the I2D/IG intensity ratio, indicating enhanced layer stacking and crystal quality. Photoluminescence (PL) measurements validated the optical bandgap, which diminished as the MoS2 content increased, indicating enhanced light absorption and reduced recombination. Hall effect measurements showed that the composite films had fewer carriers and higher mobility. Furthermore, films were successfully deposited on soda-lime glass substrates. This is a low-cost, ecofriendly, and low-temperature method for photonic and optoelectronic applications. These results highlight the advantages of alternating PLD-grown nanographene-MoS2 composite for high-performance photodetectors and offer recommendations for optimizing material composition and deposition parameters for future electronic and optoelectronic devices.