Radiative recombination of excitons in the transition-metal dichalcogenides MoS2:Cl2 and WS2:Br2

Intercalated halogen molecules as radiative centers in transition metal dichalcogenides layered crystals

“…In contrast to isoelectronically doped GaP or Si [12], where in the absence of external perturbations [13] the j-j coupling is manifested as a so-called A -B spectral doublet, the excitonic spectra of the layered TX 2 compounds, due to the lower symmetry, involve at least three zero-phonon lines. The redistribution of the PL intensity between the A, B and C lines with increasing temperature for the investigated compounds has been explained in [10] and [14], taking into account the well-known temperature behaviour of the bound excitons' radiative life-time s R (T) [11,15].…”

Quantum‐Engineered Devices Based on 2D Materials for Next‐Generation Information Processing and Storage

“…Furthermore, spatially controlled reliable intercalation doping of 2D-TMDs has also been established experimentally [296] which may be used to dope specific portions of a 2D-TFET, for example the source (Figure 11a), with utmost precision and confidence. Additionally, the long list of foreign atoms that can be introduced into 2D-TMDs, such as zero-valent metals (Cu 0 , Co 0 , Ni 0 ) [296,297] alkali metals (Li + , K + ) (Figure 11b,e), [295] gases such as FeCl 3 (Figure 11d) [298] Br 2 [299] with both p-and n-type intercalation doping options, promises the reliable complementary doping of the source-and drain-regions of a lateral 2D-TFET. [278] Therefore, although the prospects of doping through intercalation are promising, it is worthwhile to note that the need for precise doping strategy and media (gaseous, [291,292] liquid, [296] electrochemical [295] ), specific for the host 2D-TMD and its thickness, the extent of intercalation (Figure 11b,d .…”

“…Furthermore, spatially controlled reliable intercalation doping of 2D‐TMDs has also been established experimentally [ 296 ] which may be used to dope specific portions of a 2D‐TFET, for example the source (Figure 11a), with utmost precision and confidence. Additionally, the long list of foreign atoms that can be introduced into 2D‐TMDs, such as zero‐valent metals (Cu 0 , Co 0 , Ni 0 ) [ 296,297 ] alkali metals (Li + , K + ) (Figure 11b,e), [ 295 ] gases such as FeCl 3 (Figure 11d) [ 298 ] Br 2 [ 299 ] with both p‐ and n‐type intercalation doping options, promises the reliable complementary doping of the source‐ and drain‐regions of a lateral 2D‐TFET. [ 278 ]…”

High-Temperature Optical Characterization of Transition Metal Dichalcogenides by Piezoreflectance Measurements

“…TX 2 materials have also been extensively investigated because of the possible practical applications such as efficient electrodes in photoelectrochemical solar cells, catalysts in industrial applications and secondary batteries, and solid-state lubricants [2][3][4]. The observed excitonic luminescence near-indirect band-gap in TX 2 was attributed to the recombination of excitons bound on electron-attractive neutral centers, formed by halogen molecules intercalated in the van der Waals gap [6][7][8]. From a detailed lineshape fit of the piezoreflectance (PzR) spectra, the energies of the direct band-edge excitonic and higher lying interband transitions for the Mo 1-x W x S 2 and their splittings vary smoothly with the tungsten composition x [9,10].…”