Manganite/Alq3 interfaces investigated by impedance spectroscopy technique

Barra, Mario; Cassinese, A.; D’Angelo, Pasquale; Hueso, Luis E.; Graziosi, Patrizio; Dediu, V.

doi:10.1016/j.orgel.2008.05.016

Cited by 8 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…La 1 À x Sr x MnO 3 (LSMO) is a typical doped perovskite-type manganese oxide that has colossal magnetoresistance effects at room temperature and high theoretical spin polarization of 100%. The characteristics of being ferromagnetic, conductive, and stable in air make LSMO interesting both experimentally and theoretically for possible applications in spintronics and magnetic storage devices [3][4][5][6]. Many techniques have been used to grow LSMO thin films, including magnetron sputtering, pulsed laser deposition, and metal organic chemical vapor deposition (MOCVD) [7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Effects of annealing on structure and composition of LSMO thin films

Xie

Huang

Cao

et al. 2015

Physica B: Condensed Matter

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Effects of annealing on structure and composition of LSMO thin films

Xie

Huang

Cao

et al. 2015

Physica B: Condensed Matter

View full text Add to dashboard Cite

“…Barra et al, while fitting a single resonance Nyquist peak in

{LSMO/Alq}_{3}

hetero structures, they had to use two sets of parallel R–C circuits where they have attributed the second set of parallel R–C circuit to electrical properties at

{LSMO/Alq}_{3}

interface of the device. [ 12 ] While fitting the field‐dependent Z″‐ f curves for Device A (Figure 9a), we observe significant deviation of experimental data from single RC circuit model at low‐frequency peak region. This indicates carrier scattering both at LSMO bulk and LSMO/CuPc interface of the device.…”

Section: Resultsmentioning

confidence: 96%

“…[ 3 ] Moreover, a significant vacuum level shift is generally observed at LSMO/OSC interface which may lead to formation of strong interfacial dipole at the junction. [ 12 ] Hence, in our device, we may expect a basic scenario where a density of intermediate states energetically localized between

E_{normalF}

of LSMO and HOMO of CuPc is induced by the presence of interface local dipoles. It is expected that spin polarization of the intermediate states is dependent on spin resolved density of states near the Fermi level of LSMO.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Optical and Magneto‐Tunable Electrical Transport Across La_0.7Sr_0.3MnO₃, Zn_0.3Ni_0.7Fe₂O₄/CuPc Hybrid Interfaces

Deb

Nath

Pal

et al. 2023

Physica Status Solidi (a)

View full text Add to dashboard Cite

In search of multifunctionality, both light and magnetic field-dependent carrier transports have been extensively studied across magnetic/organic semiconductors (OSC) interfaces. [1][2][3][4] OSC, usually comprising of elements with small atomic numbers like carbon and hydrogen, show intrinsically weak spin-orbit coupling that may lead to long spin-relaxation times making them particularly important for spintronics device applications. [1] Obstruction of spin injection at metal/insulator interface due to conductivity mismatch may be circumvented by introducing spin transport through inorganic/organic interface in spin valve devices. [2] Cinchetti et al. observed strong spin injection of around 85%-90% across Co/CuPc (copper pthalocyanine: OSC) heterojunctions and henceforth large mean free path in CuPc. [5] Spin filtering in La 0.7 Sr 0.3 MnO 3 ðLSMOÞ=Alq 3 heterojunctions is associated with SrO segregation at outermost layer of LSMO films. [6] Most recently, significant negative TMR is observed in Co=AlO x / NaDyClq/NiFe device, which surprisingly becomes positive on reversing the device structure as NiFe=AlO x /NaDyClq/Co (NaDyClq: Mononuclear quinolone molecule). This indicates change of hybrid states at spinterfaces is an important parameter for tunnel magnetoresistance (MR) tunability in ferromagnetic/ OSC heterojunctions. [7] With the help of spin injection through spin polarized hybrid states, scientists have fabricated efficient organic spin valves (OSV), which shows considerable MR response. [8][9][10][11] However, it becomes difficult to maintain large MR at room temperature (RT) due to magnetization and spin diffusion length reduction of magnetic electrodes and OSC, respectively. Therefore, researchers are also working on impedance spectroscopy of ferromagnetic/OSC devices, which gives information about carrier scattering across those spinterfaces. Barra et al. used impedance spectroscopy technique to separate carrier scattering at bulk and interface regions in LSMO=Alq 3 heterojunction devices. [12] Riminucci et al. extracted ferromagnetic/OSC interface resistance for parallel and antiparallel states in Mq3-based molecular spin valves. [13] Enhancement of photocurrent has also been observed with light illumination across magnetic/OSC interfaces owing to generation-separation process of Frankel excitons. [4] Ahmadi et al. found enhancement of photocurrent owing to photogenerated dipole-induced recombination reduction in inorganic/organic perovskite solar cells. [14] Kasem et al. observed

show abstract

“…Previous studies of Alq3 in solar cells have been limited to the analysis of Alq3 thin-films as electron transport layers, or buffer films to prevent diffusion of cathode atoms (generally Au and Al) into the underlying optical layer . In addition, Alq3 has been studied at interfaces with oxides and metals, − but studies of Alq3/TiO 2 interfaces have yet to be reported. Here, we investigate Alq3 complexes anchored to TiO 2 -anatase surfaces by using hydroxylated arylquinoline and benzoquinoline ligands as a new class of linkers that form robust Alq3/TiO 2 molecular assemblies.…”

Section: Introductionmentioning

confidence: 99%

Visible Light Sensitization of TiO₂ Surfaces with Alq3 Complexes

et al. 2009

View full text Add to dashboard Cite

We combine ab initio DFT molecular dynamics simulations and quantum dynamics propagation of transient electronic excitations to investigate visible light sensitization of TiO2-anatase surfaces by covalent attachment of derivatized aluminum tris-(8-hydroxyquinoline) (Alq3) complexes. Hydroxylated arylquinoline and benzoquinoline ligands are introduced as robust anchoring groups to form Alq3/TiO2 molecular assemblies. We show that photoexcitation of the resulting surface complexes with visible light triggers ultrafast interfacial electron injection into the TiO2 host substrate. Furthermore, we show that derivatization of the Alq3/TiO2 surface complexes with oligothiophenes should hinder electron−hole pair recombination after photoinduced interfacial electron transfer. These findings are particularly relevant to the development of molecular based photo-optic devices based on the general class of metaloquinolate complexes Mq3, with q = 8-hydroxyquinoline and M = Al, Zn, Ga, and In, which have already attracted significant interest in the development of new technologies.

show abstract

Manganite/Alq3 interfaces investigated by impedance spectroscopy technique

Cited by 8 publications

References 28 publications

Effects of annealing on structure and composition of LSMO thin films

Effects of annealing on structure and composition of LSMO thin films

Optical and Magneto‐Tunable Electrical Transport Across La_0.7Sr_0.3MnO₃, Zn_0.3Ni_0.7Fe₂O₄/CuPc Hybrid Interfaces

Visible Light Sensitization of TiO₂ Surfaces with Alq3 Complexes

Contact Info

Product

Resources

About

Manganite/Alq3 interfaces investigated by impedance spectroscopy technique

Cited by 8 publications

References 28 publications

Effects of annealing on structure and composition of LSMO thin films

Effects of annealing on structure and composition of LSMO thin films

Optical and Magneto‐Tunable Electrical Transport Across La0.7Sr0.3MnO3, Zn0.3Ni0.7Fe2O4/CuPc Hybrid Interfaces

Visible Light Sensitization of TiO2 Surfaces with Alq3 Complexes

Contact Info

Product

Resources

About

Optical and Magneto‐Tunable Electrical Transport Across La_0.7Sr_0.3MnO₃, Zn_0.3Ni_0.7Fe₂O₄/CuPc Hybrid Interfaces

Visible Light Sensitization of TiO₂ Surfaces with Alq3 Complexes