Molecule-Dependent Quantum Yield in Photon Emission Scanning Tunneling Microscopy of Mixed Amphiphile Monolayers on Au(111)

Abstract

Contrast in photon yield between phase-separated domains of reduced and photo-oxidized alkanethiols comprising a mixed molecular monolayer on Au(111) was observed using an ultrahigh vacuum scanning tunneling microscope. The photon quantum yield of the two surface species was measured to be independent of tunneling gap width, within experimental uncertainty, suggesting a novel photon emission mechanism. The spatial resolution of the photon maps was 20 nm. These results indicate that photons emitted by a scanning tunneling microscope reveal chemical information with nanometer spatial resolution on molecularly heterogeneous surfaces.

Color imaging with a low temperature scanning tunneling microscope

“…1,2 Making use of the extremely small lateral dimension of the tunneling current filament ͑sub-͒ nanometer lateral resolution of the light emission has been achieved from metals, semiconductors, clusters, and molecules. [3][4][5][6][7][8][9] Given that the tunneling currents used for excitation are small-typically, currents in the nA range are used-the photon count rates tend to be low as well. Increasing the tunneling current in many cases leads to spontaneous surface modifications preventing reproducible experimentation.…”

Electroluminescence properties of organic nanostructures studied by scanning tunnelling microscopy

“…This observation demonstrates that a few layers of the organic molecule can serve as a buffer, which decouples organic molecules from the metallic substrate. The increased distance between tip and metallic substrate, which results from the introduction of the organic layer typically reduces the direct excitation of broadband plasmonic emission 37 although exceptions have been reported 38. Nevertheless, also for the intrinsic molecular luminescence, the plasmonic cavity modes were found to play a decisive role in coupling the local molecular luminescence to the detected electromagnetic far field 26.…”

Самоорганізація Молекул Гексадецилборної Кислоти На Атомно-Гладкій Поверхні Графіту

“…Надтонкi органiчнi плiвки (ОП), нанесенi на поверхню твердої пiдкладки, є предметом iнтенсивних експериментальних i теоретичних дослiджень [1][2][3][4]. Iнтерес до ОП пояснюється їх широким використанням у сучаснiй молекулярнiй електронiцi [5,6], зокрема в оптоелектронних [7,8] i запам'ятовувальних [9] пристроях, при розробцi сонячних батарей [10], органiчних свiтлодiодiв i польових транзисторiв [11,12]. Крiм того, впорядкованi ОП є важливими модельними об'єктами, дослiдження яких дозволяє поглибити уявлення про процеси самоорганiзацiї бiльш складних бiологiчних молекул i полiмерiв [13].…”