Indium-free transparent organic light emitting diodes with Al doped ZnO electrodes grown by atomic layer and pulsed laser deposition

Meyer, Jens; Görrn, Patrick; Hamwi, Sami; Johannes, H.‐H.; Riedl, Thomas; Kowalsky, Wolfgang

doi:10.1063/1.2975176

Cited by 131 publications

(78 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar to that of ITO, some extrinsic dopants, such as Al and Ga, are added into the ZnO films to improve the film conductivity by introducing ionic impurities. 33,45,89 Hence, these Al-doped ZnO (AZO) 33,90,91 and Ga-doped ZnO (GZO) 21,92 films show comparable optical transparency and electrical conductivity as the ITO layers and have been developed as TEs in optoelectronic devices. AZO and GZO have a work function range of 4.0 to 5.0 eV depending on the surface treatments.…”

Section: Transparent Conductive Oxidesmentioning

confidence: 99%

Transparent electrodes for organic optoelectronic devices: a review

et al. 2014

View full text Add to dashboard Cite

Abstract. Transparent conductive electrodes are one of the essential components for organic optoelectronic devices, including photovoltaic cells and light-emitting diodes. Indium-tin oxide (ITO) is the most common transparent electrode in these devices due to its excellent optical and electrical properties. However, the manufacturing of ITO film requires precious raw materials and expensive processes, which limits their compatibility with mass production of large-area, low-cost devices. The optical/electrical properties of ITO are strongly dependent on the deposition processes and treatment conditions, whereas its brittleness and the potential damage to underlying films during deposition also present challenges for its use in flexible devices. Recently, several other transparent conductive materials, which have various degrees of success relative to commercial applications have been developed to address these issues. Starting from the basic properties of ITO and the effect of various ITO surface modification methods, here we review four different groups of materials, doped metal oxides, thin metals, conducting polymers, and nanomaterials (including carbon nanotubes, graphene, and metal nanowires), that have been reported as transparent electrodes in organic optoelectronic materials. Particular emphasis is given to their optical/electrical and other material properties, deposition techniques, and applications in organic optoelectronic devices.

show abstract

Section: Transparent Conductive Oxidesmentioning

confidence: 99%

Transparent electrodes for organic optoelectronic devices: a review

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In addition, MoO 3 and WO 3 have been identified as ITO sputtering protection layer in OLEDs and organic solar cells, where a 40-60 nm thick metal oxide layer can effectively prevent the sensitive organic layers from the high kinetic particle bombardment. [34][35][36] We note that thermally evaporated metal oxides, such as MoO 3 and WO 3 , grow as sub-stoichiometric thin film, which make these materials n-type conductive due to oxygen vacancies. 37 On the other hand, a very strong chemical reduction, e.g., as a result of high evaporation temperatures or adsorbates on the surface, leads to a different metal oxide composition with a high amount of MoO 2 and WO 2 suboxides.…”

mentioning

confidence: 99%

Multifunctional oxides for integrated manufacturing of efficient graphene electrodes for organic electronics

Kidambi

Weijtens

Robertson

et al. 2015

Applied Physics Letters

View full text Add to dashboard Cite

Using multi-functional oxide films, we report on the development of an integration strategy for scalable manufacturing of graphene-based transparent conducting electrodes (TCEs) for organic electronics. A number of fundamental and process challenges exists for efficient graphene-based TCEs, in particular, environmentally and thermally stable doping, interfacial band engineering for efficient charge injection/extraction, effective wetting, and process compatibility including masking and patterning. Here, we show that all of these challenges can be effectively addressed at once by coating graphene with a thin (>10 nm) metal oxide (MoO3 or WO3) layer. We demonstrate graphene electrode patterning without the need for conventional lithography and thereby achieve organic light emitting diodes with efficiencies exceeding those of standard indium tin oxide reference devices.

show abstract

“…We should note that the conductivity of ALD fi lms depend upon several parameters, such as reactor temperature, substrate material, and Al 2 O 3 :ZnO ratio for nanolaminate fi lms. [ 19,25 ] With this in mind, further optimization of the ALD processing conditions will be needed for other BHJ materials requiring lower processing temperatures. The origin of the improved R P A values in T1 type devices compared to values in T3 type devices can be attributed to a reduction on the pinhole density in ALD nanolaminates compared to neat fi lms grown by ALD.…”

Section: Charge Recombination Layersmentioning

confidence: 99%

Inverted Tandem Polymer Solar Cells with Polyethylenimine‐Modified MoO_X/Al₂O₃:ZnO Nanolaminate as the Charge Recombination Layers

Shim

Fuentes-Hernández

Zhou

et al. 2014

Advanced Energy Materials

View full text Add to dashboard Cite

having broader absorption ranges, which span a larger portion of the solar spectrum. [ 5,6 ] Nevertheless, organic semiconductors used in PSCs having a single BHJ layer still present narrow absorption ranges that cover only a fraction of the solar spectrum; leaving more than 60% of the total photons unabsorbed. [ 7 ] Furthermore, the maximum thickness of this BHJ layer allowable for high effi ciency is limited by the transit-time of carriers within this layer. For a given set of materials and processing conditions, the optimum BHJ layer thickness strikes the best compromise between maximizing photon absorption and charge collection. [ 8 ] To overcome the limitations of PSCs with a single BHJ layer, two or more PSCs having BHJ active layers with complementary absorption ranges are connected in series by stacking them on top of one another. These so-called tandem solar cells can achieve higher power conversion effi ciency (PCE) values than single BHJ layer PSCs because they cumulatively absorb a larger portion of the solar spectrum. When the sub-cells are connected in series in a tandem PSC, the open-circuit voltage ( V OC ) of the sub-cells ideally adds up while the short-circuit current density ( J SC ) is limited by the smallest J SC generated in any of the sub-cells. [ 7,[9][10][11][12] A critical component to produce effi cient tandem PSCs is the charge recombination layer (CRL) that connects the two adjacent sub-cells. The CRL that is sandwiched between the sub-cells, needs to allow holes to be collected from one sub-cell and recombine with the electrons collected from the other sub-cell, while allowing photons to pass through it and illuminate the adjacent sub-cell. Furthermore, the CRL should have low electrical resistance to minimize power density losses. Therefore, materials comprising the CRL are required to have low absorption in the spectral region of interest, be suffi ciently conductive, and provide a large work function (WF) contrast between the two outward surfaces in contact with the photoactive layers. In addition, in tandem PSCs, the CRL also needs to allow for the fabrication of a solution-processed top photoactive layer. [ 7 ] The tandem PSC geometry dramatically impacts the pool of materials available for the realization of effi cient hole and , and a fi ll factor of 0.62 ± 0.01, resulting in a power conversion effi ciency of 6.5% ± 0.1% under simulated AM 1.5G, 100 mW cm −2 illumination.

show abstract

Indium-free transparent organic light emitting diodes with Al doped ZnO electrodes grown by atomic layer and pulsed laser deposition

Cited by 131 publications

References 17 publications

Transparent electrodes for organic optoelectronic devices: a review

Transparent electrodes for organic optoelectronic devices: a review

Multifunctional oxides for integrated manufacturing of efficient graphene electrodes for organic electronics

Inverted Tandem Polymer Solar Cells with Polyethylenimine‐Modified MoO_X/Al₂O₃:ZnO Nanolaminate as the Charge Recombination Layers

Contact Info

Product

Resources

About

Indium-free transparent organic light emitting diodes with Al doped ZnO electrodes grown by atomic layer and pulsed laser deposition

Cited by 131 publications

References 17 publications

Transparent electrodes for organic optoelectronic devices: a review

Transparent electrodes for organic optoelectronic devices: a review

Multifunctional oxides for integrated manufacturing of efficient graphene electrodes for organic electronics

Inverted Tandem Polymer Solar Cells with Polyethylenimine‐Modified MoOX/Al2O3:ZnO Nanolaminate as the Charge Recombination Layers

Contact Info

Product

Resources

About

Inverted Tandem Polymer Solar Cells with Polyethylenimine‐Modified MoO_X/Al₂O₃:ZnO Nanolaminate as the Charge Recombination Layers