Vertical 2D/3D Semiconductor Heterostructures Based on Epitaxial Molybdenum Disulfide and Gallium Nitride

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• 作者：Dmitry Ruzmetov ; Kehao Zhang ; Gheorghe Stan ; Berc Kalanyan ; Ganesh R. Bhimanapati ; Sarah M. Eichfeld ; Robert A. Burke ; Pankaj B. Shah ; Terrance P. O’Regan ; Frank J. Crowne ; A. Glen Birdwell ; Joshua A. Robinson ; Albert V. Davydov ; Tony G. Ivanov
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：March 22, 2016
• 年：2016
• 卷：10
• 期：3
• 页码：3580-3588
• 全文大小：453K
• ISSN：1936-086X

文摘

When designing semiconductor heterostructures, it is expected that epitaxial alignment will facilitate low-defect interfaces and efficient vertical transport. Here, we report lattice-matched epitaxial growth of molybdenum disulfide (MoS₂) directly on gallium nitride (GaN), resulting in high-quality, unstrained, single-layer MoS₂ with strict registry to the GaN lattice. These results present a promising path toward the implementation of high-performance electronic devices based on 2D/3D vertical heterostructures, where each of the 3D and 2D semiconductors is both a template for subsequent epitaxial growth and an active component of the device. The MoS₂ monolayer triangles average 1 μm along each side, with monolayer blankets (merged triangles) exhibiting properties similar to that of single-crystal MoS₂ sheets. Photoluminescence, Raman, atomic force microscopy, and X-ray photoelectron spectroscopy analyses identified monolayer MoS₂ with a prominent 20-fold enhancement of photoluminescence in the center regions of larger triangles. The MoS₂/GaN structures are shown to electrically conduct in the out-of-plane direction, confirming the potential of directly synthesized 2D/3D semiconductor heterostructures for vertical current flow. Finally, we estimate a MoS₂/GaN contact resistivity to be less than 4 Ω·cm² and current spreading in the MoS₂ monolayer of approximately 1 μm in diameter.