Single-step chemical vapour deposition of anti-pyramid MoS<sub>2</sub>/WS<sub>2</sub> vertical heterostructures
Xueyin Bai, Shisheng Li, Susobhan Das, Luojun Du, Yunyun Dai, Lide Yao, Ramesh Raju, Mingde Du, Harri Lipsanen, Zhipei Sun
Abstract
Van der Waals heterostructures are the fundamental building blocks of electronic and optoelectronic devices. Here we report that, through a single-step chemical vapour deposition (CVD) process, high-quality vertical bilayer MoS2/WS2 heterostructures with a grain size up to ∼60 μm can be synthesized from molten salt precursors, Na2MoO4 and Na2WO4. Instead of normal pyramid vertical heterostructures grown by CVD, this method synthesizes an anti-pyramid MoS2/WS2 structure, which is characterized by Raman, photoluminescence and second harmonic generation microscopy. Our facile CVD strategy for synthesizing anti-pyramid structures unveils a new synthesis route for the products of two-dimensional heterostructures and their devices for application.