scholarly journals Análisis de la característica corriente-voltaje de diodos orgánicos emisores de luz (OLEDs) basados en polímeros depositados por spin coating.

2010 ◽  
Vol 15 (1) ◽  
pp. 68 ◽  
Author(s):  
Henry Alberto Méndez-Pinzón ◽  
Diana Rocío Pardo-Pardo ◽  
Juan Pablo Cuéllar-Alvarado ◽  
Juan Carlos Salcedo-Reyes ◽  
Ricardo Vera ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Spin Coating ◽  
Electrical Response ◽  
Thermionic Emission ◽  
Hole Transport ◽  
Organic Layer ◽  
Electric Response ◽  
Carrier Injection ◽  
Parasitic Currents ◽  
Spin Coater

<p>Polymer-based organic light-emitting diodes (OLEDs) with the structure ITO / PEDOT:PSS / MDMO-PPV / Metal were prepared by spin coating. It is known that electroluminescence of these devices is strongly dependent on the material used as cathode and on the deposition parameters of the polymer electroluminescent layer MDMO-PPV. <strong>Objective.</strong> In this work the effect of i) the frequency of the spin coater (1000-8000 rpm), ii) the concentration of the MDMO-PPV: Toluene solution, and iii) the material used as cathode (Aluminium or Silver) on the electrical response of the devices, was evaluated through current-voltage (I-V) measurements. <strong>Materials and methods</strong>. PEDOT:PPS and MDMO-PPV organic layers were deposited by spin coating on ITO substrates, and the OLED structure was completed with cathodes of aluminium and silver. The electric response of the devices was evaluated based on the I-V characteristics. <strong>Results.</strong> Diodes prepared with thinner organic films allow higher currents at lower voltages; this can be achieved either by increasing the frequency of the spin coater or by using concentrations of MDMO-PPV: Toluene lower than 2% weight. A fit of the experimental data showed that the diodes have two contributions to the current. The first one is attributed to parasitic currents between anode and cathode, and the other one is a parallel current through the organic layer, in which the carrier injection mechanism is mediated by thermionic emission. <strong>Conclusions.</strong> The results fitting and the energy level alignment through the whole structure show that PPV-based OLEDs are unipolar devices, with current mainly attributed to hole transport.</p> <p><strong>Key words:</strong> organic semiconductors, OLEDs, electroluminescent polymers, MDMO-PPV, PEDOT:PSS, Spin coating, HOMO, LUMO, carrier injection, thermionic emission.</p><br />

scholarly journals Binary Self-Assembly of Nanocolloidal Arrays using Concurrent and Sequential Spin Coating Techniques

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 274
Author(s):  
Shih-Jyun Shen ◽  
Demei Lee ◽  
Yu-Chen Wu ◽  
Shih-Jung Liu
Keyword(s):  
Silicon Substrate ◽  
Self Assembly ◽  
Spin Coating ◽  
Processing Parameters ◽  
The Self ◽  
Silicon Substrates ◽  
Processing Conditions ◽  
Polystyrene Spheres ◽  
Optimal Processing ◽  
Spin Coater

This paper reports the binary colloid assembly of nanospheres using spin coating techniques. Polystyrene spheres with sizes of 900 and 100 nm were assembled on top of silicon substrates utilizing a spin coater. Two different spin coating processes, namely concurrent and sequential coatings, were employed. For the concurrent spin coating, 900 and 100 nm colloidal nanospheres of latex were first mixed and then simultaneously spin coated onto the silicon substrate. On the other hand, the sequential coating process first created a monolayer of a 900 nm nanosphere array on the silicon substrate, followed by the spin coating of another layer of a 100 nm colloidal array on top of the 900 nm array. The influence of the processing parameters, including the type of surfactant, spin speed, and spin time, on the self-assembly of the binary colloidal array were explored. The empirical outcomes show that by employing the optimal processing conditions, binary colloidal arrays can be achieved by both the concurrent and sequential spin coating processes.

Trap-controlled hole transport in small molecule organic semiconductors

2007 ◽  
Vol 91 (24) ◽  
pp. 242103 ◽  
Author(s):  
Arne Fleissner ◽  
Hanna Schmid ◽  
Christian Melzer ◽  
Heinz von Seggern
Keyword(s):  
Organic Semiconductors ◽  
Small Molecule ◽  
Hole Transport

The Study of Hole Injection in OLEDs with Ultra-Thin Sol-Gel TiO2 Layer

2011 ◽  
Vol 189-193 ◽  
pp. 42-46
Author(s):  
You Wang Hu ◽  
Xiao Yan Sun ◽  
Jian Duan
Keyword(s):  
Sol Gel ◽  
Hole Transport ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Hole Injection ◽  
Hole Transport Layer ◽  
Carrier Injection ◽  
Light Emitting ◽  
Organic Light ◽  
Pre Treatment

Organic light-emitting diodes (OLEDs) with inserting an ultrathin sol–gel titanium oxide (TiO2) buffer layer between the ITO anode and hole transport layer (HTL) were fabricated. The carrier injection and the device efficiency were affected by surface morphology of TiO2, which was changed by different plasma pre-treatment of ITO. Treated by CF4 plasma, the TiO2 layer is the smoothest, and treated by H2 plasma it is like island. The TiO2 layer like island is favor of carrier injection from the anode, which was attributed to the point discharged.

A cross-linkable hole transport material having improved mobility through a semi-interpenetrating polymer network approach for solution-processed green PHOLEDs

2018 ◽  
Vol 6 (29) ◽  
pp. 7750-7758 ◽  
Author(s):  
So-Ra Park ◽  
Ji-Ho Kang ◽  
Dong A Ahn ◽  
Min Chul Suh
Keyword(s):  
Spin Coating ◽  
Layer Structure ◽  
Polymer Network ◽  
Hole Transport ◽  
Interpenetrating Polymer Network ◽  
Network Approach ◽  
Solution Processed ◽  
Ink Jet Printing ◽  
Ink Jet ◽  
Jet Printing

A novel cross-linkable hole transport material (HTM) was used to form a robust layer structure upon continuous wet processes such as spin coating or ink-jet printing.

scholarly journals Comparison of NiOx thin film deposited by spin-coating or thermal evaporation for application as a hole transport layer of perovskite solar cells

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43847-43852
Author(s):  
Su-Kyung Kim ◽  
Hae-Jun Seok ◽  
Do-Hyung Kim ◽  
Dong-Hyeok Choi ◽  
Seung-Ju Nam ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spin Coating ◽  
Thermal Evaporation ◽  
Perovskite Solar Cells ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Coating Process ◽  
Spin Coating Process ◽  
Hole Transport Layers

We compared nickel oxide (NiOx) deposited by thermal evaporation and that deposited by the spin-coating process, for use in the hole transport layers of inverted planar perovskite solar cells (PSCs).

Layer Cross-Fading at Organic/Organic Interfaces in OVPD-Processed Red Phosphorescent Organic Light Emitting Diodes as a New Concept to Increase Current and Luminous Efficacy

2009 ◽  
Vol 1154 ◽  
Author(s):  
Florian Lindla ◽  
Manuel Boesing ◽  
Christoph Zimmermann ◽  
Frank Jessen ◽  
Philipp van Gemmern ◽  
...  
Keyword(s):  
Growth Rate ◽  
Hole Transport ◽  
Transport Layer ◽  
Hole Transport Layer ◽  
Organic Layer ◽  
Driving Voltage ◽  
Emission Layer ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Organic Light

AbstractThe current and luminous efficacy of a red phosphorescent organic light emitting diode (OLED) with sharp interfaces between each of the organic layers can be increased from 18.8 cd/A and 14.1 lm/W (at 1,000 cd/m2) to 36.5 cd/A (+94%, 18% EQE) and 33.7 lm/W (+139%) by the introduction of a layer cross-fading zone at the hole transport layer (HTL) to emission layer (EL) interface. Layer cross-fading describes a procedure of linearly decreasing the fraction in growth rate of an organic layer during deposition over a certain thickness while simultaneously increasing the fraction in growth rate of the following layer. For OLED processing and layer cross-fading organic vapor phase deposition (OVPD) is used. The typical observation of a roll-off in current efficacy of phosphorescent OLED to higher luminance can be reduced significantly. An interpenetrating network of a prevailing hole and a prevailing electron conducting material is created in the cross-fading zone. This broadens the recombination zone and furthermore lowers the driving voltage. The concept of layer cross-fading to increase the efficacies is suggested to be useful in multi-colored OLED stacks as well.

Solid-State Dye Sensitized Solar Cells: Effect of Hole Transport Material Properties to the Photovoltaic Performance

2013 ◽  
Vol 667 ◽  
pp. 317-323 ◽  
Author(s):  
Muhamad Nur Amalina ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Solid State ◽  
Material Properties ◽  
Spin Coating ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Hole Transport ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

The improvement of solid-state dye sensitized solar cells requires identification and understanding of hole transport material properties at various deposition process that limit the energy conversion efficiency. A well-studied of this hole collectors properties, a high efficiency ss-DSSC is highly achievable. In this research work, the copper (I) iodide (CuI) had been deposited by spin coating and mist-atomization technique. The thin films characteristics of surface morphology and electrical properties and its effect to the photovoltaic performance were investigated. The thin films morphology examined by FESEM shows smaller CuI crystal size deposited by spin coating (S1) of ~30nm. Even though, smaller particle size of hole conductor is desirable in order to achieve high pore penetration, the thin film thickness and the electrical resistivity are also essential. The CuI thin films deposited by mist-atomization (M1) shows a low resistivity of 1.77 x 10-1 Ωcm which will greatly affect the device performance. The photovoltaic performance of ss-DSSC at different method CuI deposition shows the highest efficiency of 1.05% for sample (M1) while the ss-DSSC fabricated with S1 sample shows the lowest conversion efficiency of 0.02%. The appropriate crystals size of CuI, film thickness and the electrical resistivity greatly contributed to the high filling fraction of the porous TiO2 layer and hence the cells performance.

Effect of hole transport organic layer on characteristics of hybrid photovoltaic structure

2015 ◽  
Author(s):  
A. de J. Olivares ◽  
I. Cosme ◽  
S. Mansurova ◽  
A. Kosarev ◽  
H. Martínez
Keyword(s):  
Hole Transport ◽  
Organic Layer
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