Impact of Surface Dipole on Resonant Electron Injection in Scanning Tunneling Spectroscopy

Abstract

Resonant electron injection and first-principles calculations are utilized to study singleadsorbed selenium (Se) atom on a Si(111)-7×7 surface. Theoretical calculations indicate that a negative dipole of 0.61 eV forms toward the adsorbed Se atom due to electron transfer from the associated Si atoms. The formation of surface dipole modifies the effective tunneling barrier height and causes a shift in the energy of the resonant state formed in the vacuum gap between the tip and the sample surface. The experimental data imply that an outward negative surface dipole of 0.61 eV causes a resonant electron injection bias shift to high voltage of about 0.45 V.

Multifunctional Buffer Layer Engineering for Efficient and Stable Wide‐Bandgap Perovskite and Perovskite/Silicon Tandem Solar Cells

“…Moreover, a surface dipole can increase the local work function and hinder efficient electron extraction. [39] The z-component of the dipole moment (D z ) is calculated to be maximal for the PVSK/C 60 system (4.10 Debye) and is reduced to 2.31 Debye after the insertion of AlO x interlayer (Figure S9), consistent with the trend of work functions measured by UPS. [40] X-ray photoelectron spectroscopy (XPS) was provided to further insight into the chemical modification of the perovskite.…”

Efficient and stable perovskite-silicon tandem solar cells through contact displacement by MgF x

“…The presence of a surface dipole at the metal-fluoride/C60 interface can increase the local work function and hinder efficient electron extraction (56). The z-component of the dipole moment (Dz) is calculated to be maximal for the FAPI/C60 system (7.24 Debye, Fig.…”

“…Fig. S1 to S27Tables S1 References(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56) …”