Scientists at Rice University in Texas have demonstrated a way to “write” light sources and nanoscale wiring directly onto crystals using a finely focused beam of electrons — a development that could simplify the manufacture of next-generation chips and optoelectronic devices.
The technique, described in Nano Letters, employs a high-energy electron beam as what researchers call a “nanoscale pencil.” By firing the beam into sheets of molybdenum oxide, an ultrathin van der Waals material, the team was able to remove oxygen atoms from the crystal lattice. The resulting atomic defects enhanced both electrical conductivity and light emission, producing glowing blue traces narrower than the width of a DNA strand.
“This is a one-step way to draw light sources and wires at scales where traditional lithography struggles,” said Hae Yeon Lee, Assistant Professor of Materials Science and Nanoengineering and one of the study’s corresponding authors.
The research team relied on a newly installed cathodoluminescence spectroscopy system at Rice’s Shared Equipment Authority to both create and observe these changes in real time. According to Postdoctoral Researcher Yifeng Liu, the co-lead author, the patterns became “hundreds of times more conductive” while retaining strong and stable light emission.
The ability to integrate such features directly onto chips could be significant for industries seeking ever-smaller, more efficient optoelectronic components.
Analysts have pointed to van der Waals materials (layered structures where atomic layers are held together by strong in-plane covalent bonds and weak, out-of-plane van der Waals forces) as a promising platform for innovation because their atomically thin layers can be tuned with unusual precision.
Rice’s work suggests that the approach may be applicable beyond molybdenum oxide to a broader family of van der Waals oxides, potentially offering a new toolkit for miniaturised device design.
The study was backed by Rice University alongside funding from the US Defense Advanced Research Projects Agency, the US National Science Foundation, and research agencies in Japan and South Korea.
