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

Abstract

Here, we propose a novel DNA-based doping method on MoS2 and WSe2 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 MoS2 by Ln-DNA is between 6 × 109 and 2.6 × 1010 cm−2. The p-doping change on WSe2 by Ln-DNA is adjusted between −1.0 × 1010 and −2.4 × 1010 cm−2. In Eu3+ or Gd3+-Co-DNA doping, a light p-doping is observed on MoS2 and WSe2 (~1010 cm−2). However, in the devices doped by Tb3+ or Er3+-Co-DNA, a light n-doping (~1010 cm−2) occurs. A significant increase in on-current is also observed on the MoS2 and WSe2 devices, which are, respectively, doped by Tb3+- and Gd3+-Co-DNA, due to the reduction of effective barrier heights by the doping. In terms of optoelectronic device performance, the Tb3+ or Er3+-Co-DNA (n-doping) and the Eu3+ or Gd3+-Co-DNA (p-doping) improve the MoS2 and WSe2 photodetectors, respectively. We also show an excellent absorbing property by Tb3+ ions on the TMD photodetectors.

Giant Enhancement of Photoluminescence Emission in WS2-Two-Dimensional Perovskite Heterostructures

“…As two-dimensional (2D) semiconductors, transition metal dichalcogenides (TMDCs) have emerged as highly intriguing materials in the fields of optics 1,2 , electronics 3,4 , catalysis 5 , and mechanics 6 .…”

Doping of Monolayer Transition-Metal Dichalcogenides via Physisorption of Aromatic Solvent Molecules

“…Accordingly, electron/hole concentrations modified by physisorbed molecules effectively influence the formation of excitons and trions in TMDs. Although a great effort has been devoted to the non-covalent functionalization of monolayer TMDs via molecular physisorption to improve fundamental properties 16 such as photoluminescence tuning, [9][10][17][18] electron/hole doping [19][20] and device contact improvement, 21 the simple interaction of a functionalized benzene ring (being frequently a fragment of solvent molecules) and monolayer TMDs has not yet been fully unraveled. 22 Despite the fact that typical solvent molecules are seemingly considered as inert media, aromatic molecules have been proved to cause n-or pdoping with distinct functional groups through π-π interactions with graphene.…”

Modulation of Optical and Electrical Characteristics by Laterally Stretching DNAs on CVD-Grown Monolayers of MoS2

“…The A 1g Raman mode shift of 3 cm −1 corresponds to an increase of ∼1.4 × 10 13 /cm 2 in the electron density [37]. The presence of a negatively charged phosphate group in the backbone of the DNA may be the origin of such electron doping effect [24,25]. In addition, the tensile strain may be responsible for the observed red-shift of PL peak energy in our DNA/1L-MoS 2 , since tensile strain is known to reduce the bandgap of 1L-MoS 2 [10,36] and thus we expect stretched DNA molecules could cause the band gap modulation of 1L-MoS 2 .…”

“…While there have been many efforts to create hybrid structures of TMDs for enhanced physical and chemical characteristics [19][20][21][22], the hybridization of biomaterials and TMDs is relatively rare. Recently, ultra-high sensitivity fieldeffect transistor (FET) sensor using DNA-TMD system has been demonstrated [23], and DNA inducing doping effect on thick TMDs materials have been introduced [24,25]. Biomolecules and TMD materials hold significant potential for the development of extremely small devices with increasingly complex functionality, which could open various applications in bioelectronics.…”