Paper 2D-TuP2
Black Phosphorus and Endohedral-Graphene Hybrids for Novel Optoelectronic Devices

Tuesday, October 22, 2019, 6:30 pm, Room Union Station B

Among the various two-dimensional (2D) materials, graphene is a material of immense technological importance given its ballistic transport which provides opportunities for high-speed field-effect transistors (FETs). Other mono-elemental 2D materials such as black phosphorus (BP) provide a thickness-dependent, direct band gap ranging from ~ 0.3 eV in the bulk to ~1.5 eV in the monolayer limit. Here, in the first part of the work, we report on the integration of zero-dimensional materials with 2D graphene membranes to enhance the optoelectronic properties of the photodetectors. Quantum dot-graphene optoelectronic devices are discussed where mechanically exfoliated graphene flakes are used in a two-terminal device configuration. The zero-dimensional materials used in this work were cluster endohedral fullerenes, Sc₃N@C₈₀, and monometallic endohedral fullerene, La@C₈₂, based on their electron-accepting and electron-donating abilities, respectively. Temperature-dependent and wavelength-dependent optoelectronic properties of the 0D-2D graphene-based hybrids will be presented. In the second part of the work, we will also show the chemical exfoliation of BP to form optoelectronic devices with protecting layers to enhance the stability of the BP. Here, we present liquid exfoliation approaches to obtain BP by sonication in organic solvent such as 1-cyclohexyl-2-pyrrolidone (CHP), N-methyl-2-pyrrolidone (NMP) at ambient conditions. We compare the structural properties of black phosphorus through Raman Spectroscopy analysis, Photoluminescence (PL) and two-terminal electronic device measurements to demonstrate its enhanced device stability.