Orbital Tomography
  • Home
  • Publications
  • People
  • Menu Menu

Max Niederreiter » People

Active members
  • Go back to directory.
  • Add to Address Book.

Max Niederreiter

MSc Student Karl-Franzens-Universität GrazInstitute of Physics – Surface Science
Website: Surface Science

Biographical Info

2021

1.

M. Niederreiter

Integer charge transfer in organic adsorbates on metallic substrates Masters Thesis

2021.

Abstract | BibTeX

@mastersthesis{Niederreiter2021,
title = {Integer charge transfer in organic adsorbates on metallic substrates},
author = {M. Niederreiter},
year = {2021},
date = {2021-06-01},
urldate = {2021-06-01},
abstract = {In this work charge transfer into molecular monolayers on metal substrates is studied. The first goal was to find clear experimental evidence for the coexistence of charged and uncharged copper-phthalocyanine CuPc molecules in monolayers (ML) on silver surfaces. The first findings were made using scanning tunneling microscopy STM, where images of CuPc monolayers on Ag(111) showed two distinct molecular species, which could be identified as charged and neutral from the appearance of their orbital structure. This is further supported by Konod resonance observations with scanning tunneling spectroscopy STS. On Ag(100) larger scale images also indicated two distinct species with different contrast. These findings are complemented by the results obtained with angle resolved ultraviolet photoemission spectroscopy ARUPS. Studying the sub-monolayer growth of CuPc on Ag(100) strongly suggests the coexistence of a charged and an uncharged CuPc species within the first ML. Estimates of the fraction of charged molecules could be made from the intensities of orbital features in ARUPS and from the measured work function behaviour. STM and ARUPS both suggest the coexistence of integer charge and neutral molecules on the metal substrate. Even beyond that, three different methods of determining the ratio of charged CuPc molecules have been used, which ultimately yield similar results and therefore support each other. These findings are in contradiction to the conventional wisdom that equilibration will lead to all molecules experiencing similar charge transfer. Furthermore, displacement studies with pentacene 5A and CuPc performed with ARUPS allow a deeper understanding of the process of charge transfer and the role the electron affinity (EA) plays in it. It could clearly be shown that CuPc displaces 5A both on the metallic Ag(100) and on the dielectric MgO(100) surface. This is remarkable since the binding mechanisms on these two surfaces would generally be considered very different from each other, with hybridization on the metal and charge transfer on the dielectric being the dominant processes. This strongly suggests that indeed the EA and therefore charge transfer play a central role in the binding process of the adsorbates. This work furthers the understanding of charge transfer on metals and paves the way for understanding displacement reactions and suggests a means of controlling and predicting molecular heterostructures.
},
keywords = {},
pubstate = {published},
tppubtype = {mastersthesis}
}

Close

In this work charge transfer into molecular monolayers on metal substrates is studied. The first goal was to find clear experimental evidence for the coexistence of charged and uncharged copper-phthalocyanine CuPc molecules in monolayers (ML) on silver surfaces. The first findings were made using scanning tunneling microscopy STM, where images of CuPc monolayers on Ag(111) showed two distinct molecular species, which could be identified as charged and neutral from the appearance of their orbital structure. This is further supported by Konod resonance observations with scanning tunneling spectroscopy STS. On Ag(100) larger scale images also indicated two distinct species with different contrast. These findings are complemented by the results obtained with angle resolved ultraviolet photoemission spectroscopy ARUPS. Studying the sub-monolayer growth of CuPc on Ag(100) strongly suggests the coexistence of a charged and an uncharged CuPc species within the first ML. Estimates of the fraction of charged molecules could be made from the intensities of orbital features in ARUPS and from the measured work function behaviour. STM and ARUPS both suggest the coexistence of integer charge and neutral molecules on the metal substrate. Even beyond that, three different methods of determining the ratio of charged CuPc molecules have been used, which ultimately yield similar results and therefore support each other. These findings are in contradiction to the conventional wisdom that equilibration will lead to all molecules experiencing similar charge transfer. Furthermore, displacement studies with pentacene 5A and CuPc performed with ARUPS allow a deeper understanding of the process of charge transfer and the role the electron affinity (EA) plays in it. It could clearly be shown that CuPc displaces 5A both on the metallic Ag(100) and on the dielectric MgO(100) surface. This is remarkable since the binding mechanisms on these two surfaces would generally be considered very different from each other, with hybridization on the metal and charge transfer on the dielectric being the dominant processes. This strongly suggests that indeed the EA and therefore charge transfer play a central role in the binding process of the adsorbates. This work furthers the understanding of charge transfer on metals and paves the way for understanding displacement reactions and suggests a means of controlling and predicting molecular heterostructures.

Close

Alumni
© Copyright - Orbital Tomography
  • Legal Notice
  • Privacy Policy
Scroll to top

This site uses cookies. By continuing to browse the site, you are agreeing to our use of cookies.

Accept settingsHide notification onlySettings

Cookie and Privacy Settings



How we use cookies

We may request cookies to be set on your device. We use cookies to let us know when you visit our websites, how you interact with us, to enrich your user experience, and to customize your relationship with our website.

Click on the different category headings to find out more. You can also change some of your preferences. Note that blocking some types of cookies may impact your experience on our websites and the services we are able to offer.

Essential Website Cookies

These cookies are strictly necessary to provide you with services available through our website and to use some of its features.

Because these cookies are strictly necessary to deliver the website, refusing them will have impact how our site functions. You always can block or delete cookies by changing your browser settings and force blocking all cookies on this website. But this will always prompt you to accept/refuse cookies when revisiting our site.

We fully respect if you want to refuse cookies but to avoid asking you again and again kindly allow us to store a cookie for that. You are free to opt out any time or opt in for other cookies to get a better experience. If you refuse cookies we will remove all set cookies in our domain.

We provide you with a list of stored cookies on your computer in our domain so you can check what we stored. Due to security reasons we are not able to show or modify cookies from other domains. You can check these in your browser security settings.

Other external services

We also use different external services like Google Webfonts, Google Maps, and external Video providers. Since these providers may collect personal data like your IP address we allow you to block them here. Please be aware that this might heavily reduce the functionality and appearance of our site. Changes will take effect once you reload the page.

Google Webfont Settings:

Google Map Settings:

Google reCaptcha Settings:

Vimeo and Youtube video embeds:

Privacy Policy

You can read about our cookies and privacy settings in detail on our Privacy Policy Page.

Privacy Policy
Accept settingsHide notification only