The triplet state in tris-(8-hydroxyquinoline)aluminum

Cölle, Michael; Gärditz, C.; Braun, Markus

doi:10.1063/1.1808249

Cited by 48 publications

(35 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the observation of a marked increase at 40 K in the lifetime of the hole-electron triplet states in Alq 3 (ref. 28) suggests there is a corresponding decrease of the spin relaxation rate. Furthermore, the electron paramagnetic resonance line intensity in Alq 3 exhibits a similar step-like increase below 40 K (ref.…”

Section: Quantitative Analysismentioning

confidence: 99%

Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation

et al. 2008

View full text Add to dashboard Cite

Electronic devices that use the spin degree of freedom hold unique prospects for future technology. The performance of these 'spintronic' devices relies heavily on the efficient transfer of spin polarization across different layers and interfaces. This complex transfer process depends on individual material properties and also, most importantly, on the structural and electronic properties of the interfaces between the different materials and defects that are common to real devices. Knowledge of these factors is especially important for the relatively new field of organic spintronics, where there is a severe lack of suitable experimental techniques that can yield depth-resolved information about the spin polarization of charge carriers within buried layers of real devices. Here, we present a new depth-resolved technique for measuring the spin polarization of current-injected electrons in an organic spin valve and find the temperature dependence of the measured spin diffusion length is correlated with the device magnetoresistance.R ecently great efforts have been undertaken to use the spin degree of freedom in electronic devices. These activities are fuelled by the potential prospects of spin-electronic (or 'spintronic') devices for example in terms of increased processing speed and integration, non-volatility, reduced power consumption, multifunctionality and their suitability for quantum computing 1 . The most common method for using the spin in devices is based on the alignment of the electron spin ('up' or 'down') relative to either a reference magnetic field or the magnetization orientation of a ferromagnetic layer. Device operation normally proceeds with measuring a quantity such as the electrical current that depends on how the degree of spin alignment is transferred across the device. The so-called 'spin valve' is a prominent example of such a spin-enabled device that has already revolutionized hard-drive read heads and magnetic memory 1 . The efficient transfer of spin polarization in real device structures remains one of the most difficult challenges in spintronics, because it is dependent on more than just the properties of the individual materials that comprise the device.Recently 2,3 , the use of organic materials in spintronics has become of significant interest, primarily owing to their ease and small cost of processing and electronic and structural flexibility. Furthermore, the extremely long spin coherence times found in organic materials offer considerable advantages over other materials 3 . This favourable property is related to two factors, first the weak spin-orbit coupling of light elements such as carbon and second to the small nuclear hyperfine interaction 4,5 . The latter arises because the electron transport in π-conjugated molecules is normally confined to molecular states, delocalized to the carbon rings, the predominant isotope of which, 12 C, has zero nuclear spin 4 .A common way to measure spin diffusion is based on time-resolved optical techniques, where spin-polarized charge carrie...

show abstract

Section: Quantitative Analysismentioning

confidence: 99%

Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation

et al. 2008

View full text Add to dashboard Cite

show abstract

“…In the steady state, the ratio of the triplet to singlet concentration should scale as the ratio of the lifetimes. Given that triplet excitons have a lifetime at least a thousand times longer than singlets, [55][56][57] their concentration will be considerably higher in a working device and hence their dissociation would be expected to predominate. The change in efficiency of an OLED with applied magnetic field is a direct measure of the increase in singlet concentration per injected carrier.…”

Section: Resultsmentioning

confidence: 99%

Modeling of positive and negative organic magnetoresistance in organic light-emitting diodes

et al. 2012

View full text Add to dashboard Cite

The organic magnetoresistance of aluminium tris(8-hydroxyquinoline) based organic light-emitting diodes has been modeled using the triplet polaron interaction coupled with exciton dissociation. We have demonstrated that each of the processes is proportional to the exciton concentration over a wide range of operating conditions for a number of devices with a wide range of layer thicknesses. This work demonstrates that using a magnetic field to perturb the operation of a working organic device is particularly valuable in that it provides a new technique for studying a range of processes affecting current transport such as polaron trapping, triplet-polaron interactions, and exciton dissociation in fully working devices.

show abstract

“…The green emission is caused by a mer-isomer, while the blue emission is caused by a fac-isomer [2,3]. Four crystalline phases of α, β, γ, and δ have been observed for Alq 3 crystals [3,4,6].…”

Section: Introductionmentioning

confidence: 89%

“…The Alq 3 molecule has facial and meridianal isomers (hereinafter called fac-and mer-isomers, respectively) [1][2][3][4][5][6][7][8]. The green emission is caused by a mer-isomer, while the blue emission is caused by a fac-isomer [2,3].…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence characteristics of green and blue emitting Alq3 organic molecules in crystals and thin films

Tsuboi

Torii²

2010

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

The triplet state in tris-(8-hydroxyquinoline)aluminum

Cited by 48 publications

References 33 publications

Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation

Direct measurement of the electronic spin diffusion length in a fully functional organic spin valve by low-energy muon spin rotation

Modeling of positive and negative organic magnetoresistance in organic light-emitting diodes

Photoluminescence characteristics of green and blue emitting Alq3 organic molecules in crystals and thin films

Contact Info

Product

Resources

About