Symmetry-selective ultrafast charge transfer via cyano end groups at the PDIF-CN▫$_2$▫–Au(111) interface

Kladnik, Gregor (avtor), Cassinese, Antonio (avtor), Schio, Luca (avtor), Goldoni, Andrea (avtor), Morgante, Alberto (avtor), Floreano, Luca (avtor), Cvetko, Dean (avtor)

Cyano-functionalized perylene diimides provide a platform for engineering orbital-specific electronic transparency at organic‒metal interfaces. Here we resolve the adsorption geometry, orbital symmetry, and ultrafast charge-transfer dynamics of PDIF-CN▫$_2$▫ on Au(111) using polarization-dependent NEXAFS, XPS, resonant Auger spectroscopy with core-hole-clock analysis, and STM. Molecules in the monolayer lie flat with out-of-molecular plane polarized cyano-derived ▫$\pi^*$▫ orbitals aligned toward Au(111). Although the overall electronic structure remains largely molecular, the nearly degenerate cyano ▫$\sigma^*(\pi)/\pi^*(\pi)$▫ doublet becomes distinctly split at the interface, enabling symmetry-selective coupling of cyano orbitals. We use Auger spectator shifts to quantify bidirectional charge exchange within the N 1s core-hole lifetime, yielding injection of ▫$\sim$▫0.43 e▫$^-$▫ from Au into cyano ▫$\pi^*(\pi)$▫ orbital and the transfer of ▫$\sim$▫0.17 e▫$^-$▫ in the opposite direction. These findings establish cyano end groups as symmetry-selective gateways for femtosecond charge transfer at molecule‒metal interfaces.

• Jezik: Angleški jezik
• Ključne besede: thin films, interfaces, charge transfer, Auger spectroscopy
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: Str. 6983-6990
• Številčenje: Vol. 26, iss. 21
• PID: 20.500.12556/RUL-183097
• UDK: 544
• ISSN pri članku: 1530-6984
• DOI: 10.1021/acs.nanolett.6c01061
• COBISS.SI-ID: 278874883
• Datum objave v RUL: 04.06.2026

Gradivo je del revije

• Naslov: Nano letters
• Skrajšan naslov: Nano lett.
• Založnik: American Chemical Society
• ISSN: 1530-6984
• COBISS.SI-ID: 18341927

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: tanki filmi, površine, prenos naboja, Augerjeva spektroskopija