Rate My Professor Pengpeng Zhang

Professor Zhang leads the Nanoscale Surface and Interface Group, focusing on the characterization and engineering of surfaces and interfaces in low-dimensional materials such as van der Waals layered materials, nanowires, and quantum dots. Utilizing scanning probe microscopy and device characterization, his research investigates fundamental properties of low-dimensional electronic and photovoltaic materials and manipulates these properties through surface and interface engineering. Key projects include heterostructures of FeSn Kagome metals for distance-dependent flat band evolution, lateral heterostructures of metal dichalcogenides inducing semiconductor-to-topological insulator transitions via stress propagation, thin films of organic charge transfer complexes to understand mixed valence effects on insulator-to-metal transitions, hetero-interfaces between organic and inorganic materials via anisotropic crystalline organic step-flow growth on deactivated Si surfaces, and scanning probe studies of organic and perovskite photovoltaics. Fabrication techniques employed encompass molecular beam epitaxy and ultrahigh vacuum chemical vapor deposition. Notable achievements feature the first observation of long-ranged ordered step-flow growth in organic thin films, revelations of heterogeneous grain boundary behaviors impacting high-efficiency perovskite solar cell performance, microscopic elucidation of physics at mixed valence boundaries in organic charge transfer complexes, and demonstration of core-shell lateral heterostructures transforming two-dimensional transition metal dichalcogenides from semiconductor to topological insulator. Select publications are "Distance-dependent evolution of flat bands in Kagome-honeycomb lateral heterostructure in FeSn" (ACS Nano 18, 8768, 2024), "Semiconductor to topological insulator transition induced by stress propagation in metal dichalcogenide (TMD) core-shell lateral heterostructures" (Materials Horizons 8, 1029, 2021), "Microscopic understanding of mixed valence effect on insulator-to-metal transition" (J. Phys. Chem. Lett. 11, 8352, 2020), Phys. Rev. Lett. 110, 086107 (2013) and 115, 096101 (2015), "Electronic transport in nanometre-scale silicon-on-insulator membranes" (2006), "Hybrid strategies in nanolithography" (2010), and "Self-assembly of carboranethiol isomers on Au {111}: intermolecular interactions determined by molecular dipole orientations" (2009).