SUBJECT AREAS NANOSCALE MATERIALS, NANOSCALE DEVICES, SEMICONDUCTORS, ELECTRONIC PROPERTIES AND DEVICES, SYNTHESIS AND PROCESSING Correspondence and requests for materials should be addressed to S. F. Yu Siu.Fung.Yu@inet.polyu.edu.hk and H.Y. Yang (yanghuiying@sutd.edu.sg). Selective Decoration of Au Nanoparticles on Monolayer MoS2 Single Crystals Yumeng Shi,1,# Jing-Kai Huang,2,# Limin Jin,3,# Yu-Te Hsu,2 Siu Fung Yu, 3,* Lain-Jong Li, 2, 4 and Hui Ying Yang1,* 1. Pillar of Engineering Product Development, Singapore University of Technology and Design, Singapore 138682, Singapore 2. Institute of Atomic and Molecular Sciences Academia Sinica, Taipei 10617, Taiwan 3. Departments of Applied Physics, the Hong Kong Polytechnic University, Hung Hum, Kowloon, Hong Kong, China 4. Department of Physics National Tsing Hua University, HsinChu 300, Taiwan. 1 Figure S1. Surface profile of MoS2 monolayers on sapphire substrate shows a typical thickness of 0.71 nm, the inset showing the corresponding AFM images. The white dot line indicates where the surface profile was taken. 2 Figure S2. Figure (A) shows the EDX taken from the surface of MoS2 without Au NPs. Figure (B) gives XEDS spectra taken from the Au NPs/ CVD-MoS2. The strong Cu peaks are likely originated from the Cu grids. The other elements such as Si, O and C, could be the impurities introduced by the chemical etchant during the transfer process. 3 Figure S3. SEM image shows a broken MoS2 film on sapphire substrate after Au NPs decoration. Inset shows the enlarged back folded region of MoS2 film. Au NPs tend to adsorb on the edge part of the broken film. 4 Figure S4. HRTEM image of CE-MoS2 before Au NPs decoration. The inset shows the FFT pattern taken from the marked area. The HRTEM and FFT pattern for CE-MoS2 suggest that the CE-MoS2 films exhibit poor crystallinity and smaller domain size compared with to the CVD-MoS2. 5 Figure S5. The figure shows the I-Vg curve of Au doped and pristine MoS2 EDLT in log scale on the y-axis. Reference 1. Lin, Y.-C.; Zhang, W.; Huang, J.-K.; Liu, K.-K.; Lee, Y.-H.; Liang, C.-T.; Chu, C.-W.; Li, L.-J. Nanoscale 2012, 4, (20), 6637-6641. 2. Lee, Y.-H.; Zhang, X.-Q.; Zhang, W.; Chang, M.-T.; Lin, C.-T.; Chang, K.-D.; Yu, Y.-C.; Wang, J. T.-W.; Chang, C.-S.; Li, L.-J.; Lin, T.-W. Advanced Materials 2012, 24, (17), 2320-2325. 3. Eda, G.; Yamaguchi, H.; Voiry, D.; Fujita, T.; Chen, M.; Chhowalla, M. Nano Letters 2011, 11, (12), 5111-5116. 6