Recently, the research team of Academician Yu Shuhong of the University of Science and Technology of China has used the "two-step catalytic growth" strategy to achieve the on-demand synthesis of high-quality, blue-light active ZnSe quantum wires, which will help promote the application of ZnSe environmental protection quantum wires and is expected to provide a rich material library for solar fuels and optoelectronics.
Schematic diagram of synthesis control of semiconductor nanowires, a is the solution-solid-solid-solid phase catalytic growth mechanism, and b is the independent regulation of the radial and axial dimensions of ZnSe quantum wires based on the "two-step catalytic growth" strategy, picture from the paper
Quantum wires are one-dimensional semiconductor nanowires with quantum limiting effects, which have application value in optoelectronics, photochemical conversion and other fields. Among them, ZnSe quantum wires are the most typical class of non-heavy metal semiconductors in addition to cadmium-based semiconductors, which are harmless to the environment. However, the previous ZnSe nanowires are either very thin, with a strong quantum limiting effect, which only shows ultraviolet absorption; or it is very coarse, with block material characteristics, no obvious exciton absorption, so it is difficult to achieve quantum limiting effect modulation in the blue light region.
So how can the radial and axial dimensions of ZnSe quantum wires be precisely controlled to enable on-demand synthesis to facilitate their further application?
This time, the team of academician Yu Shuhong of the University of Science and Technology of China developed a "two-step catalytic growth" strategy, which can control the diameter and length of ZnSe quantum lines independently, with high precision and a wide range, and realize the accurate preparation of ZnSe quantum lines, thus successfully establishing a new bridge between the magic number size ZnSe quantum wire and the block-like ZnSe nanowire. The results were published in the National Science Review.
Image from national science review
The researchers found that there is a new epitaxial growth orientation at the interface between the cubic phase catalyst endpoint and the ZnSe quantum line of the fiber zinc ore, which can dynamically promote the formation of ultra-fine, stack-free ZnSe quantum lines. These quantum lines have a strong quantum limiting effect, uniform size, high crystal phase purity, and thus exhibit ultra-narrow exciton absorption characteristics in the blue light region, and their half-height full width (FWHM) can reach less than 13 nm (nanometers). After surface thiol passivation, they further eliminated the electron trapping trap on the surface of the quantum wire, thereby extending the carrier life and enabling an efficient photocatalytic hydrogen production process.
The "two-step catalytic growth" strategy of the UNIVERSITY of Science and Technology of China can be applied to the precise construction of a variety of colloidal nanowires, which is expected to provide a rich material library for the development of solar fuels and optoelectronics in the future.