ZnSnN2 Fabrication Using Combinatorial Reactive Sputtering and Its Study of Piezo-related Properties

Abstract

Fabrication of the new class of ternary nitrides (Zinc Tin Nitride (ZnSnN2)) is full of challenges because of its high formation energies However it is thermodynamically stable and owns a direct band gap of approximately 2 eV which is excellent for photocatalysis Furthermore ZnSnN2 is an environmentally friendly material since it only contains earth-abundant and non-toxic elements – Zn and Sn and it possesses high tolerance to acidic and basic environments enabling applications at a wide range of tough environments Orthorhombic ZnSnN2 has a non-centrosymmetric structure enabling piezotronic and piezophototronic properties which is demonstrated to further enhance the efficiency of photocatalysis in this study In this study ZnSnN2 was successfully obtained from the Zn-Sn3N4 composition spread using RF reactive sputtering on a FTO substrate We found the Locations 1 and 2 exhibited the substantial amount and excellent crystallinity of ZnSnN2 Pna21 and Pmc21 orthorhombic structures of ZnSnN2 was identified from the measured XRD patterns via the deconvolution algorithm of the peaks at around 33o and 35o In addition HCl(aq) was used to etch away metal Sn in the sample for the piezo-related properties measurement The asymmetric I-V characteristics and the Schottky barrier height as a function of pressures suggested the piezotronic and piezophototronic effects which further supported the successful fabrication of orthorhombic structure of ZnSnN2

Date of Award	2016 Aug 31
Original language	English
Supervisor	Kao-Shuo Chang (Supervisor)