Saved in:
Bibliographic Details
Main Authors: Ghafoor, Atif, Neuvonen, Santeri, Tran, Thinh, Segura, Oscar Moreno, Sun, Yitao, Pavlyukh, Yaroslav, Tuovinen, Riku, Lado, Jose L., Kezilebieke, Shawulienu
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.29286
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917372667887616
author Ghafoor, Atif
Neuvonen, Santeri
Tran, Thinh
Segura, Oscar Moreno
Sun, Yitao
Pavlyukh, Yaroslav
Tuovinen, Riku
Lado, Jose L.
Kezilebieke, Shawulienu
author_facet Ghafoor, Atif
Neuvonen, Santeri
Tran, Thinh
Segura, Oscar Moreno
Sun, Yitao
Pavlyukh, Yaroslav
Tuovinen, Riku
Lado, Jose L.
Kezilebieke, Shawulienu
contents Deterministic control of excitonic properties is key to advancing nanoscale optoelectronic and quantum technologies and to understanding diverse physical, optical, chemical, and biological phenomena. At the molecular scale, these properties can be tuned through chemical modification, local-environment influence or charge-state manipulation. Yet, direct control of a molecule's transition dipole moment and its resulting light emission via atomic-scale structural modification has remained elusive. Here, using scanning tunnelling microscopy-induced luminescence, we show that a single structural parameter-the vertical displacement of the central metal atom in a planar phthalocyanine molecule on a decoupling layer-enables active tuning of the transition dipole, allowing either suppression or enhancement of emission. Exploiting this control, we realized a tunable homodimer switchable among three optical states: non-emissive, single-molecule-like emissive, and coupled states exhibiting subradiant and superradiant modes, directly revealing intermolecular dipole-dipole coupling. We further demonstrate a heterodimer in which resonant energy transfer can be turned on or off simply by controlling the acceptor's transition dipole moment. These findings not only establish atomic-scale displacement as a general strategy for optical molecular switching, but also demonstrate the reconfigurable engineering of excitonic interactions within molecular assemblies.
format Preprint
id arxiv_https___arxiv_org_abs_2603_29286
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Atomically Reconfigurable Single-Molecule Optoelectronics
Ghafoor, Atif
Neuvonen, Santeri
Tran, Thinh
Segura, Oscar Moreno
Sun, Yitao
Pavlyukh, Yaroslav
Tuovinen, Riku
Lado, Jose L.
Kezilebieke, Shawulienu
Materials Science
Deterministic control of excitonic properties is key to advancing nanoscale optoelectronic and quantum technologies and to understanding diverse physical, optical, chemical, and biological phenomena. At the molecular scale, these properties can be tuned through chemical modification, local-environment influence or charge-state manipulation. Yet, direct control of a molecule's transition dipole moment and its resulting light emission via atomic-scale structural modification has remained elusive. Here, using scanning tunnelling microscopy-induced luminescence, we show that a single structural parameter-the vertical displacement of the central metal atom in a planar phthalocyanine molecule on a decoupling layer-enables active tuning of the transition dipole, allowing either suppression or enhancement of emission. Exploiting this control, we realized a tunable homodimer switchable among three optical states: non-emissive, single-molecule-like emissive, and coupled states exhibiting subradiant and superradiant modes, directly revealing intermolecular dipole-dipole coupling. We further demonstrate a heterodimer in which resonant energy transfer can be turned on or off simply by controlling the acceptor's transition dipole moment. These findings not only establish atomic-scale displacement as a general strategy for optical molecular switching, but also demonstrate the reconfigurable engineering of excitonic interactions within molecular assemblies.
title Atomically Reconfigurable Single-Molecule Optoelectronics
topic Materials Science
url https://arxiv.org/abs/2603.29286