Controlled Bipolar Doping of One-Dimensional van der Waals Nb 2 Pd 3 Se 8 .

Tailoring the electrical properties of one-dimensional (1D) van der Waals (vdW) materials is desirable for their applications toward electronic devices by exploiting their unique characteristics. However, 1D vdW materials have not been extensively investigated for modulation of their electrical properties. Here we control doping levels and types of 1D vdW Nb ₂ Pd ₃ Se ₈ over a wide energy range by immersion in AuCl ₃ or β-nicotinamide adenine dinucleotide (NADH) solutions, respectively. Through spectroscopic analyses and electrical characterizations, we confirm that the charges were effectively transferred to Nb ₂ Pd ₃ Se ₈ , and the dopant concentration was adjusted to the immersion time. Furthermore, we make the axial p-n junction of 1D Nb ₂ Pd ₃ Se ₈ by a selective area p-doping using the AuCl ₃ solution, which exhibits rectifying behavior with an I _forward / I _reverse of 81 and an ideality factor of 1.2. Our findings could pave the way to more practical and functional electronic devices based on 1D vdW materials.