Ultra-low Doping on Two-Dimensional Transition Metal Dichalcogenides using DNA Nanostructure Doped by a Combination of Lanthanide and Metal Ions

• Published in: Scientific reports 2016-02, Vol.6 (1), p.20333, Article 20333
• Main Authors: Kang, Dong-Ho, Dugasani, Sreekantha Reddy, Park, Hyung-Youl, Shim, Jaewoo, Gnapareddy, Bramaramba, Jeon, Jaeho, Lee, Sungjoo, Roh, Yonghan, Park, Sung Ha, Park, Jin-Hong
• Format: Article
• Language: English
• Subjects: 639/925/926/1049; 639/925/927/1007; Cations, Divalent - chemistry; Chalcogens - chemistry; Chalcogens - metabolism; Deoxyribonucleic acid; DNA; DNA - chemistry; Humanities and Social Sciences; Ions; Ions - chemistry; Lanthanoid Series Elements - chemistry; Metals; multidisciplinary; Nanostructures - chemistry; Science; Transition Elements - chemistry
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep20333

Here, we propose a novel DNA-based doping method on MoS 2 and WSe 2 films, which enables ultra-low n- and p-doping control and allows for proper adjustments in device performance. This is achieved by selecting and/or combining different types of divalent metal and trivalent lanthanide (Ln) ions on DNA nanostructures, using the newly proposed concept of Co-DNA (DNA functionalized by both divalent metal and trivalent Ln ions). The available n-doping range on the MoS 2 by Ln-DNA is between 6 × 10 9 and 2.6 × 10 10  cm −2 . The p-doping change on WSe 2 by Ln-DNA is adjusted between −1.0 × 10 10 and −2.4 × 10 10  cm −2 . In Eu 3+ or Gd 3+ -Co-DNA doping, a light p-doping is observed on MoS 2 and WSe 2 (~10 10  cm −2 ). However, in the devices doped by Tb 3+ or Er 3+ -Co-DNA, a light n-doping (~10 10  cm −2 ) occurs. A significant increase in on-current is also observed on the MoS 2 and WSe 2 devices, which are, respectively, doped by Tb 3+ - and Gd 3+ -Co-DNA, due to the reduction of effective barrier heights by the doping. In terms of optoelectronic device performance, the Tb 3+ or Er 3+ -Co-DNA (n-doping) and the Eu 3+ or Gd 3+ -Co-DNA (p-doping) improve the MoS 2 and WSe 2 photodetectors, respectively. We also show an excellent absorbing property by Tb 3+ ions on the TMD photodetectors.