The
rise of two-dimensional (2D) graphene-cognated crystals with
nonzero band gaps like transition metal dichalcogenides has led to
a rapidly increasing interest in their dimensionality-dependent anisotropic
properties, which bear high potential for ultrathin electronics. 2D
crystals of the III–VI metal chalcogenide InSe represent a
new kind of material class predestined for the use in optoelectronic
applications as highly responsive photodetectors and field-effect
transistors. We present a solution-processable method for 2D ultrathin
InSe nanosheets (≤5 nm with ligands, lateral sizes up to ∼800
μm) with a detailed characterization of the sheet formation
by a lamellar ligand templated growth. Optical and electrical transport
properties, as well as in depth analysis of the crystal structure
and stoichiometry of the colloidal nanosheets by electron and atomic
force microscopy, X-ray photoelectron spectroscopy, and scattering
methods complete this comprehensive study on a wet-chemical alternative
to produce ultrathin InSe nanosheets.
Solution-processable, two-dimensional semiconductors are promising optoelectronic materials which could find application in low-cost solar cells. Lead sulfide nanocrystals raised attention since the effective band gap can be adapted over a wide range by electronic confinement and observed multi-exciton generation promises higher efficiencies. We report on the influence of the contact metal work function on the properties of transistors based on individual two-dimensional lead sulfide nanosheets. Using palladium we observed mobilities of up to 31 cm(2) V(-1) s(-1). Furthermore, we demonstrate that asymmetrically contacted nanosheets show photovoltaic effect and that the nanosheets' height has a decisive impact on the device performance. Nanosheets with a thickness of 5.4 nm contacted with platinum and titanium show a power conversion efficiency of up to 0.94% (EQE 75.70%). The results underline the high hopes put on such materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.