Synthesis of Semiconductor Crystalline Boron Quantum Dots Through Dual‐Pulsed Laser Ablation Technique

Zero‐dimensional boron structures have attracted significant interest because of their diverse phase structures and unique properties. In this work, semiconductor crystalline boron quantum dots (BQDs) were successfully synthesized using a novel dual‐pulsed laser ablation method with high‐energy 532 and 1064 nm lasers in oleic acid. The developed approach enabled efficient synthesis of crystalline BQDs with controlled sizes and synthesis durations by regulating the interface between boron powder and the solvent. The prepared BQDs exhibited uniform distribution, narrow thickness distribution, excellent solubility, and high stability in aqueous solutions. The average particle diameters obtained after 4, 3, and 2 h of ablation were 2.45, 3.44, and 4.58 nm, respectively. Optical measurements confirmed strong quantum confinement effects, with the bandgap increasing from 1.80 eV for bulk boron to 2.25, 2.15, and 2.10 eV for the synthesized BQDs. Room‐temperature electrical conductivities of 1.46, 1.25, and 1.17 S/cm were achieved, which are significantly higher than that of bulk boron (7.5 × 10 ⁻³  S/cm). BQDs with higher conductivity were applied in a nonvolatile rewritable memory device, exhibiting a high ON/OFF current ratio of 6 × 10 ³ , low operating voltage (0.1 V), and good stability for potential nanoelectronic and optoelectronic applications.