Current mapping of lead phthalocyanine thin films in the presence of gaseous dopants

Madhuri, Priya K.; Santra, Pralay K.; Bertram, Florian; John, Neena S.

doi:10.1039/c9cp03873f

Cited by 8 publications

(9 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The development of MPcs and their unique structural, electrical, and optical properties was important due to the discovery of their semiconductor functionality in recent years. These characteristics resulted in their utilization in various electronic devices applications, such as organic field effect transistors, organic light emitting diodes, gas sensors, supercapacitors, spintronics, electrocatalysis, magnetic resonance imaging, and others [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. MPc semiconductors have high hole mobilities (μ) [ 11 ], for instance, the CuPc μ is between 10 −8 –10 −7 m 2 /Vs [ 12 , 13 , 14 ] and is high enough for employment as a p-semiconductor on photovoltaic devices [ 11 , 12 , 13 , 14 , 15 ], whereas the ZnPc μ value is around 10 −10 m 2 /Vs [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of Conduction Mechanisms in Disodium Phthalocyanine-Based Organic Diodes for Flexible Electronics

et al. 2020

View full text Add to dashboard Cite

In the current work, flexible diodes with flat heterojunction and dispersed heterojunction architecture were manufactured with to study the behavior of thin films of disodium phthalocyanine (Na2Pc). The thin film devices, using the electronic acceptor tetracyano-π-quinodimethane (TCNQ), were fabricated by high-vacuum thermal evaporation with annealing post-treatment in order to optimize their behavior. Theoretical calculations based on density functional theory (DFT) with dispersion force analysis were carried out in order to simulate molecular interactions and to establish the nature of the weak interactions between the Na2Pc and TCNQ fragments. In the optimized structure of the coupled Na2Pc-TCNQ, the electronic relationship between phthalocyanine and TCNQ was observed to be through hydrogen bonds with bond lengths of 2.94 and 3.13 Å. Dispersed heterojunction device current density values were considerably larger than those of the flat heterojunction device. Barrier heights of 1.024 and 0.909 eV and charge mobilities of 10−10 and 10−9 m2/Vs for the flat heterojunction device and the dispersed heterojunction device, respectively, were observed. A small effect was observed on the electrical properties by thermal annealing on the flat heterojunction device. The threshold voltage decreased from 1.203 to 1.147 V and φb decreased by 0.001 eV.

show abstract

Section: Introductionmentioning

confidence: 99%

Comparative Study of Conduction Mechanisms in Disodium Phthalocyanine-Based Organic Diodes for Flexible Electronics

et al. 2020

View full text Add to dashboard Cite

show abstract

“…In our earlier studies, we have reproducibly obtained different crystallites of PbPc on substrates such as HOPG, Au(111), Si and SiO 2 . Detailed studies using Raman spectroscopy and 2D-GIXRD show ordered monoclinic and triclinic moieties on HOPG and Si substrates, respectively, while the Au(111) surface gives rise to disordered fractions due to the absence of long-range ordering [9,26]. In the present study, the presence of single-layer graphene on SiO 2 has a templating effect and induces a monoclinic packing of PbPc in the face-on configuration.…”

Section: Resultsmentioning

confidence: 45%

“…The signature of monoclinic moieties along the q z direction indicates that the PbPc molecules exhibit ordered stacking, normal to the substrate plane. This type of vertical ordering known as cofacial arrangement can promote charge transport in the vertical direction [6,9,26]. Further, a small fraction of the (320) reflection is measured at an azimuthal angle ( Figure 3c).…”

Section: Resultsmentioning

confidence: 96%

“…The 2D-XRD also shows the presence of a peak at 0.49 Å −1 along the q z direction, which may be assigned to the (200) reflection of the monoclinic phase or the (001) reflection of the triclinic phase, occurring at the same positions with d = 12.82 Å (Figure 3a,b). This less intense peak indicates that there is a small number of crystallites arranged in an edge-on configuration [26]. There is a peak at 0.53 Å −1 corresponding to the (100) reflection of the triclinic phase in the q xy plane with d = 11.87 Å.…”

Section: Resultsmentioning

confidence: 99%

“…Our previous theoretical studies have shown that the PbPc molecule exclusively adopts a face-on configuration on an unsupported graphene layer owing to π-π and van der Waals interactions. For multilayer depositions, ordered π stacking of the macrocycles with Pb-up configuration is expected due to the dominant π-π interactions between the Pc macrocycle and the graphene layer [9,26].…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

Madhuri¹,

Sagade²,

Santra³

et al. 2020

Beilstein J. Nanotechnol.

Self Cite

View full text Add to dashboard Cite

The influence of single-layer graphene on top of a SiO2/Si surface on the orientation of nonplanar lead phthalocyanine (PbPc) molecules is studied using two-dimensional grazing incidence X-ray diffraction. The studies indicate the formation of a mixture of polymorphs, i.e., monoclinic and triclinic forms of PbPc with face-on (lying down) and edge-on (standing up) PbPc orientations, respectively. The formation of monoclinic fractions is attributed to the presence of the graphene layer directing the π interactions between the highly delocalized macrocycles. The competing interfacial van der Waals forces and molecule–molecule interactions lead to the formation of a small fraction of triclinic moieties. The nanoscale electrical characterization of the thin PbPc layer on graphene by means of conducting atomic force microscopy shows enhanced vertical conductance with interconnected conducting domains consisting of ordered monoclinic crystallites through which the charge transfer occurs via tunneling. These results show the importance of a templating layer to induce the formation of a required phase of PbPc suitable for specific device applications.

show abstract

Optical and electrical evaluation of a nylon 11-ZnO film incorporation in disodium phthalocyanine heterostructures

Hamui,

Vergara,

Sánchez

2023

SN Appl. Sci.

View full text Add to dashboard Cite

Disodium phthalocyanine (Na2Pc) has been considered as promising organic semiconductor for optoelectronic applications, however, Na2Pc-based devices are not being fully studied. To study the Na2Pc as active layer for optoelectronic devices, and also the effect of the incorporation of a nylon 11-ZnO film within the device heterostructure, in this work two heterojunction cells of Ag/Na2Pc + TCNQ/triphenylamine/p-Si/Al and Ag/nylon 11-ZnO/Na2Pc + TCNQ/triphenylamine/p-Si/Al were fabricated by vacuum thermal evaporation technique. The topography of the heterostructures was analyzed by atomic force microscopy. Later, the films that form the heterostructure were optically characterized by Ultraviolet-visible spectroscopy and the optical band gap and the Urbach energy were obtained. The values of the optical gap for the films are between 2.08 and 2.93 eV. The value of Urbach energy is lower for the pristine triphenylamine film, and higher for the film composed of nylon and ZnO. Moreover, the two heterostructures present a strong photoluminescence in the visible region. On other hand, by introducing the nylon 11-ZnO film in the heterostructure shows an important increase of the short circuit current density (Jsc), conductivity and photocurrent values, indicative of a better mobility and more carriers generation. For this heterostructure a mean 79.7% external quantum efficiency and 0.48 mA/cm2 Jsc were obtained. These results indicate that these heterostructures can be used toward organic solar cell applications and remark on the large effect of the nylon 11-ZnO dielectric film addition on their performance.

show abstract

Current mapping of lead phthalocyanine thin films in the presence of gaseous dopants

Abstract: Iodine doping in nonplanar Pb(ii)phthalocyanine causes significant structural reorganization and enhanced conductance with nanoscale conducting pathways and improved sensitivity towards other gaseous adsorbates.

Cited by 8 publications

References 45 publications

Comparative Study of Conduction Mechanisms in Disodium Phthalocyanine-Based Organic Diodes for Flexible Electronics

Comparative Study of Conduction Mechanisms in Disodium Phthalocyanine-Based Organic Diodes for Flexible Electronics

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

Optical and electrical evaluation of a nylon 11-ZnO film incorporation in disodium phthalocyanine heterostructures

Contact Info

Product

Resources

About