Influence of Oxygen Adsorption on Electronic Structure of Iron Phthalocyanine

Białek, Beata; Brągiel, P.

doi:10.12693/aphyspola.89.443

Cited by 4 publications

(2 citation statements)

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“…The increase in conductance of MPcs when exposed to humidity and or oxygen atmosphere has been reported by other researchers and has been explored for sensing applications. ,− The effects of oxygen adsorption or p-type dopant, in general, on the energy levels of doped CuPc molecule are well studied using photoemission studies . However, several arguments have been reported concerning the interaction of MPcs with water molecules such as a p-dopant or a Lewis base .…”

Section: Resultsmentioning

confidence: 94%

Nanoscale Conductance in Lead Phthalocyanine Thin Films: Influence of Molecular Packing and Humidity

Madhuri

Kaur²,

Ali³

et al. 2017

J. Phys. Chem. C

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The influence of crystalline phase and disorder on vertical charge transport in nonplanar metallophthalocyanines is studied by depositing thin films of shuttlecock molecules, lead phthalocyanine (PbPc), and SnPc on various substrates such as highly oriented pyrolytic graphite (HOPG), silicon, and gold and investigating the structural and electrical characteristics of the films. The films represent three cases of crystalline packing such as monoclinic, triclinic, and disordered phases, directed by the substrate−molecule interactions and intermolecular interactions. Theoretical calculations are performed to understand the molecular orientations on the substrate and give insights into the possible origin of ordered and disordered packing. Vertical charge transport in the films is studied by employing conducting atomic force microscopy and compared with bulk electrical measurements. It is revealed that the monoclinic phase of PbPc on HOPG exhibits two orders of magnitude higher conductance than silicon or gold and is related to the ordered stacking of the macrocycles through which the charge transport is facilitated. Local conductance mapping reveals inhomogeneity among conducting domains and is correlated with the grain structure. The charge transport is best fitted with tunneling mechanism for nanoscale and space-charge-limited current for bulk measurements. The presence of humidity is also shown to influence the nanoscale charge transport with enhanced conductance. Under saturating humidity conditions, the conductance is found to decrease. This study emphasizes the implication of graphite or graphite-like platforms that promote the ordered stacking of delocalized molecular systems for enhanced vertical charge transport.

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Section: Resultsmentioning

confidence: 94%

Nanoscale Conductance in Lead Phthalocyanine Thin Films: Influence of Molecular Packing and Humidity

Madhuri

Kaur²,

Ali³

et al. 2017

J. Phys. Chem. C

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“…13 Although the experimental and theoretical literature pertaining to MPc sensor applications is extensive, a basic understanding of gas chemisorption onto these metal coordination complexes is lacking. 18,19 Of the studies that did allow for geometric relaxation, the focus was on analyte binding to the hydrogen bridge of the metal-free phthalocyanine. 17 A few computational studies have investigated the interaction of an analyte with the MPc but did not allow the MPcanalyte complex to relax geometrically.…”

Section: Introductionmentioning

confidence: 99%

A density functional theory study on the binding of NO onto FePc films

Tran

Kummel

2007

The Journal of Chemical Physics

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To develop an atomistic understanding of the binding of NO with iron phthalocyanine (FePc), the interaction between NO (an electron withdrawing gas) and NH3 (an electron donating gas) with an isolated FePc molecule (monomer) was compared with density functional theory. The simulations show that NO strongly chemisorbs to the Fe metal and physisorbs to all the nonmetal sites. Additionally, when NO physisorbs to the inner ring nitrogens, NO subsequently undergoes a barrierless migration to the deep chemisorption well on the Fe metal. Conversely, NH3 only weakly chemisorbs to the Fe metal and does not bind to any other sites. Projected density of states simulations and analysis of the atomic charges show that the binding of NO to the FePc metal results in a charge transfer from the Fe metal to the NO chemisorbate; the opposite effect is observed for the binding of NH3 to the Fe metal. Simulations of NO binding to the Fe metal of a monolayer FePc film and FePc trimer were also performed to show that intermolecular FePc-FePc interactions have a negligible effect on the FePc electronic structure and NO binding.

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