Presentation Information
[23a-22A-1]Synthesis of Large-Area GeS Thin Films Using Vapor Transport Method
〇Qinqiang Zhang1, Ryo Matsumura1, Naoki Fukata1 (1.NIMS)
Keywords:
Germanium monosulfide (GeS)
Large-area two-dimensional layered semiconductors are attractive for development of next-generation electronics and optoelectronics. Germanium monosulfide (GeS) is one of the potential materials due to its direct bandgap of 1.6 eV and high electron mobility of 3680 cm2/Vs. In this study, large-area crystallized GeS thin films are synthesized by using the vapor transport method with two-independent heating zones. The temperature in Zone 1 reached the required level 20 min earlier than that of in Zone 2 to achieve the pre-deposited GeS layer. When the growth time is 20 min, only bulk-cluster-like GeS with a small area can be observed. When the growth time is 35 min, the synthesized GeS shows a thin-film-like structure. The diameter of one GeS thin film domain is around 400 µm. The lattice fringe of synthesized GeS thin films shows an orthorhombic structure which is confirmed by transmission electron microscope. The single-crystalline electron diffraction pattern of synthesized GeS thin films can be obtained when the observed area of the selected area electron diffraction is reduced to around 200 nm. In addition, the growth process for larger single-crystal GeS is currently under development.