Kim, Doyeon Park, Kidong Shojaei, Fazel Debela, Tekalign Terfa Kwon, Ik Seon Kwak, In Hye Seo, Jaemin Ahn, Jae Pyoung Park, Jeunghee Kang, Hong Seok 2024-01-19T19:33:49Z 2024-01-19T19:33:49Z 2022-01-25 2019-07 2050-7488 https://pubs.kist.re.kr/handle/201004/119805 Recently there have been extensive efforts to develop novel two-dimensional (2D) layered structures, owing to their fascinating thickness-dependent optical/electrical properties. Herein, we synthesized thin GeP nanosheets that had a band gap (E-g) of 2.3 eV, which is a dramatic increase from the value in the bulk (0.9 eV) upon exfoliation. This E-g value is close to that of the GeP monolayer predicted by first-principles calculations (HSE06 functional). The calculations also indicate a strong dependence of E-g on the number of layers (2.306, 1.660, 1.470, and 1.397 eV for mono-, bi-, tri-, and tetralayers, respectively), and that the band edge positions are suitable for water splitting reactions. Field-effect transistor devices were fabricated using the p-type GeP nanosheets of various thicknesses, and the devices demonstrated a significant decrease in the hole mobility but an increased on-off ratio as the layer number decreased. The larger on-off ratio (10(4)) for the thinner ones is promising for use in novel 2D (photo)electronic nanodevices. Further, liquid-exfoliated GeP nanosheets (thickness = 1-2 nm) deposited on Si nanowire arrays can function as a promising photoanode for solar-driven water-splitting photoelectrochemical (PEC) cells. Based on the calculated band offset with respect to the Fermi levels for the two half-reactions in the water splitting reaction, the performance of the PEC cell can be explained by the formation of an effective p-GeP/n-Si heterojunction. English ROYAL SOC CHEMISTRY Thickness-dependent bandgap and electrical properties of GeP nanosheets Article 10.1039/c9ta04470a 1 JOURNAL OF MATERIALS CHEMISTRY A, v.7, no.27, pp.16526 - 16532 JOURNAL OF MATERIALS CHEMISTRY A 7 27 16526 16532 N scie scopus 000475689800044 2-s2.0-85068782483 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article ELECTRONIC-STRUCTURE CARRIER MOBILITY GEAS SEMICONDUCTOR MONOLAYER CRYSTAL