Fabrication of iron carbide by plasma-enhanced atomic layer deposition

Iron carbide (Fe 1− x C x ) thin films were successfully grown by plasma-enhanced atomic layer deposition (PEALD) using bis( N, N ′-di- tert -butylacetamidinato)iron(II) as a precursor and H 2 plasma as a reactant. Smooth and pure Fe 1− x C x thin films were obtained by the PEALD process in a layer-by-layer film growth fashion, and the x in the nominal formula of Fe 1− x C x is approximately 0.26. For the wide PEALD temperature window from 80 to 210 °C, a saturated film growth rate of 0.04 nm/cycle was achieved. X-ray diffraction and transition electron microscope measurements show that the films grown at deposition temperature 80–170 °C are amorphous; however, at 210 °C, the crystal structure of Fe 7 C 3 is formed. The conformality and resistivity of the deposited films have also been studied. At last, the PEALD Fe 1− x C x on carbon cloth shows excellent electrocatalytic performance for hydrogen evolution.