Laser-induced desorption for patterning photoluminance in C₆₀/MoS₂ heterostructure

Chuan-Che Hsu^1*, Kang-Yao Ma², Che-Ming Liu², Chien-Chen Hsu², Yann-Wen Lan², Wen-Chin Lin²

¹Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
²Department of Physics, National Taiwan Normal University, Taipei, Taiwan

* Presenter:Chuan-Che Hsu, email:hsu.cc@nsrrc.org.tw

In this study, C₆₀ was deposited on a few-layer MoS₂ flake by electron beam evaporation in ultra-high vacuum. We studied morphology, Raman spectra, and photoluminescence (PL) spectra of these systems. MoS₂ flakes were grown on SiO₂/Si(100) substrates by using chemical vapor deposition. In morphology, the surface roughness of 5-nm C₆₀/MoS₂ is ±1 nm; as C₆₀ increases to 9-20 nm, the roughness is saturated at ±2 nm without further improvement. When C₆₀ was deposited on MoS₂, no change was observed in the Raman spectrum, indicating that the van der Waals contact between C₆₀ and MoS₂ was very weak and would not cause significant changes in the microstructure. As the thickness of C₆₀ increases, the PL peak shifts from 1.83 eV dominated by MoS₂ to 1.69 eV dominated by C₆₀. Furthermore, we observed that the local desorption induced by the CW laser was confirmed on the C₆₀/MoS₂ heterostructure. The laser power of around 10 mW/µm² is enough for the desorption of 20 nm C₆₀ from a MoS₂ flake and can be used to create designed patterns with a resolution around 500 nm. In addition to the morphological structure, CW laser-induced C₆₀ desorption to achieve patterned PL on C₆₀/MoS₂. This method can be applied to the manufacturing of functional nanodevices combining 0-dimensional and two-dimensional materials in the future.

Keywords: MoS₂, C₆₀/MoS₂, C₆₀ desorption, Nano pattern