Research Highlight

Growth of 2D Pentagonal PdSe2 Crystals with High Mobility

(a) Large crystals of PdSe2 grown by CVD display high electron mobility and anisotropic properties due to their (b,c) buckled crystal structure resulting from (d) pentagonal bonding.

Scientific Achievement

A chemical vapor deposition method was developed to successfully synthesize layered crystals of PdSe2, a pentagonal 2D material, with exceptional optical and electrical properties approaching that of exfoliated crystals.

Significance and Impact

The scalable synthesis of novel 2D crystals to assess their anisotropic properties is essential for the rapid exploration and development of future electronic devices.

Research Details

– Few layer PdSe2 crystals were grown by CVD and characterized by atomic-resolution STEM, STM, and transport measurements that showed high electron mobility up to ~ 294 cm2 V-1 s-1.
– Polarized Raman spectroscopy and second harmonic generation mapping characterized the strong in-plane optical anisotropy of the pentagonal, puckered 2D PdSe2 structure.
– A theoretical model based on kinetic Wulff construction theory and DFT was developed to explain the shape evolution of PdSe2 crystals.
 

Y. Gu, H. Cai, J. Dong, Y. Yu, A. N. Hoffman, C. Liu, A. Oyedele, Y.-C. Lin, Z. Ge, A. A. Puretzky, G. Duscher, M. F. Chisholm, P. D. Rack, C. M. Rouleau, Z. Gai, X. Meng, F. Ding, D. B. Geohegan, and K. Xiao, Two-Dimensional Palladium Diselenide with Strong In-Plane Optical Anisotropy and High Mobility Grown by Chemical Vapor Deposition," Adv. Mater. 1906238 (2020). DOI: 10.1002/adma.201906238