Atomic Layer Deposition of Emerging 2D Semiconductors, HfS2 and ZrS2, for Optoelectronics

Miika Mattinen from Prof. Mikko Ritala's group, University of Helsinki, reports the ALD growth of 2D HfS2 and ZrS2—the potential rivals of the hot favorite 2D semiconductors MoS2 and WSe2. 

Abstract: Semiconducting 2D materials are studied intensively because of their promising performance in diverse applications from electronics to energy storage and catalysis. Recently, HfS2 and ZrS2 have emerged as potential rivals for the commonly studied 2D semiconductors such as MoS2 and WSe2, but their use is hindered by the difficulty of producing continuous films. 

Herein, we report the first atomic layer deposition (ALD) processes for HfS2 and ZrS2 using HfCl4 and ZrCl4 with H2S as the precursors. We demonstrate the deposition of uniform and continuous films on a range of substrates with accurately controlled thicknesses ranging from a few monolayers to tens of nanometers. The use of semiconductor industry-compatible precursors and temperatures (approximately 400 °C) enables facile upscaling of the process. The deposited HfS2 and ZrS2 films are crystalline, smooth, and stoichiometric with oxygen as the main impurity. 

Source : Atomic Layer Deposition of Emerging 2D Semiconductors, HfS2 and ZrS2, for Optoelectronics

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By Abhishekkumar Thakur