The energy band alignment at the interface between mechanically exfoliated few-layer NiPS3 nanosheets and ZnO

• Published in: Current applied physics 2016, 16(3), , pp.404-408
• Main Authors: Kuo, Cheng-Tai, Balamurugan, Karuppannan, Shiu, Hung Wei, Park, Hyun Ju, Sinn, Soobin, Neumann, Michael, Han, Moonsup, Chang, Young Jun, Chen, Chia-Hao, Kim, Hyeong-Do, Park, Je-Geun, Noh, Tae Won
• Format: Article
• Language: English
• Subjects: Band offset; Exfoliation; Nickel phosphorous trisulfide; Photoemission spectroscopy; Zinc oxide; 물리학
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2016.01.001

We have studied the electronic structure and interfacial properties of mechanically exfoliated few-layer NiPS3 van der Waals crystals on ZnO/Nb:SrTiO3 substrates using scanning photoelectron microscopy and spectroscopy. The conducting ZnO layer enhances the visibility of few-layer NiPS3 on Nb:SrTiO3 and prevents charging effects in photoemission. We experimentally determined a type-II band alignment at the NiPS3/ZnO interface. The valence band offset (VBO) of few-layer NiPS3/ZnO is 2.8 ± 0.09 eV, and the conduction band offset is 1.0 ± 0.09 eV. Moreover, we found an increase of ∼0.3 eV in VBO as decreasing NiPS3 thickness, suggesting electronic coupling or charge transfer at the NiPS3/ZnO interface. [Display omitted] •We fabricated few-layer NiPS3 nanosheets on ZnO/Nb:SrTiO3 by mechanical exfoliation method.•Insertion of ZnO layer enhances visibility of few-layer NiPS3 and prevents charging effects for photoemission studies.•The band offset of NiPS3/ZnO is determined using micro-beam XPS measurements.•Type-II band alignment is observed at the interface of NiPS3 and ZnO.•The values of valence band offset increase as NiPS3 layer number decreases.