Chemical vapor deposition of zirconium(IV) sulfide on flexible polymers

The emerging optoelectronic material family of transition metal dichalcogenides may be useful in flexible electronics. However, only MoS2 has been grown directly as thin films on polymer substrates, owing in part to the high deposition temperatures typically required to prepare these materials. Changing vapor deposition chemistry can allow much lower film growth temperatures. We show that when using tetrakis(dimethylamido)zirconium(IV), Zr(NMe2)4, and H2S as precursors, low-temperature chemical vapor deposition affords films of zirconium(IV) sulfide (ZrS2) directly on polymer substrates. Stoichiometric and crystalline ZrS2 films can be deposited with good adhesion on polyimide (Kapton) and polyether ether ketone (PEEK) substrates at 150–200 °C. The films deposited on polydimethylsiloxane (PDMS) substrates were stoichiometric and crystalline, but not well adhered. Films on all substrates were polycrystalline with small (20–30 nm) grains, highly oriented in the [001] direction of the 1T ZrS2 phase. The films grown on PEEK have resistivities ca. 625 Ω cm, two orders of magnitude higher than ZrS2 films deposited at 800–1000 °C from ZrCl4 and sulfur. The films grown on Kapton are similarly conductive, whereas films on PDMS are not conductive.