Topological insulators (TI) are a novel class of materials that exhibit an insulating bulk phase, as well as metallic surface transport properties. Bi2Se3 is a layered semiconductor, which has the widest bandgap in all proposed TIs and is most promising to achieve room temperature spintronic devices. Manipulation of the bulk carrier concentration in Bi2Se3 nanoplates can be achieved by Sb doping and field effect modulation. Along with the potential for future applications and doping potential, Bi2Se3 is relatively inexpensive and simple to synthesize, making it an ideal candidate for the study of the surface states of TIs. Previous reports of solution grown Bi2Se3 nanoplates have either yielded plates too thick or with too small a plate area to make single nanoplate electronic characteristics possible. Also, Sb-doping of these solution grown nanoplates have produced nanoplates with only ~1% doped Sb. We report here a solution synthesis for Bi2Se3 nanoplates that provide thin (~6nm) plates with improved plate widths (3.5-10 µm), suitable for electronic measurements. Size control of Bi2Se3 nanoplates was done by varying the temperature, precursor, concentration, and reaction length of the synthesis. Sb-doping was performed by controlling the ratio of bismuth to antimony in the synthesis. The undoped and doped nanoplates have been made into field effect transistors to measure the carrier concentration and mobility of individual plates. Sb-doping has been achieved at levels higher than previously reported for solution grown Bi1-xSbxSe3 nanoplates and depletion of the bulk carrier has been observed. The synthesis and characterization of these phases will be presented and discussed.

Size control and Sb doping of solution grown two-dimensional Bi2Se3 nanoplates

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.