Adsorption of TCNQ and F4-TCNQ molecules on hydrogen-terminated Si(1 1 1) surface: van der Waals interactions included DFT study of the molecular orientations

First-Principles Calculation of Charge Transfer at the Silicon–Organic Interface

“…The hydrogen-terminated silicon (100) surface with 1 × 1 reconstruction (Si(100):H) is used in all the calculations. Parts a and b of Figure show the structure of TCNQ on the Si(100):H surface in the parallel orientation (PO), which is found to be the most stable configuration of the TCNQ molecule or SAM on the silicon surface. , The smallest distance d PO between TCNQ and the Si(100):H surface is 2.32 Å, and chemical bonds do not form at the interface. We construct the band decomposition, as shown in Figure a, of the hybrid structure in terms of maximally localized Wannier functions (MLWFs). , As the Wannier functions near the interface are well localized (Figure S3 in the Supporting Information), the band structures of each part of the hybrid system are clearly identified.…”

“…1(a) and 1(b) show the structure of TCNQ on Si(100):H surface as in the parallel orientation (PO) which is found to be the most stable configuration of TCNQ molecule or SAM on silicon surface. 25,27 The smallest distance dPO between TCNQ and the Si(100):H surface is 2.32 Å and no chemical bonds form at the interface. We construct the bands decomposition, as shown in Fig.…”

“…Previous study has seen efficient n-type doping of silicon by cobaltocene with transferred electron density of 2×10 13 cm -2 . 13 Several other studies [23][24][25][26][27] show that strong acceptors such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) could withdraw electrons from silicon resulting in p-type doping. However, questions like how many charges per molecule are transferred in these HIO systems or which molecule is the best to efficiency inject holes to silicon, are not addressed.…”

Gas adsorption effects on electronic and magnetic properties of triangular graphene antidot lattices

“…Both of these adsorbates are strong electron acceptors. As a result, the adsorption of these large molecules on graphene surface modifies strongly the electric and magnetic properties of the surface [24][25][26][27][28][29]. Nevertheless, the interplay between these molecules and GALs has, to our knowledge, not been reported previously.…”

“…The charge transfer between the gas molecules and graphene surface depends strongly on the orientation of the adsorbate with respect to the surface but it is almost independent of the adsorption site. On the other hand, F4TCNQ and TCNQ are large molecules with high electron affinity [24][25][26][27][28][29]. TCNQ is an organic compound with chemical formula C 12 N 4 H 4 acting as an electron acceptor.…”