Novel Electrodes from Solution-Processed Layer-Structure Materials

Frey, Gitti L.; Reynolds, Kieran J.; Friend, Richard H.

doi:10.1002/1521-4095(20020219)14:4<265::aid-adma265>3.0.co;2-m

Cited by 60 publications

(48 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Metal oxides were used as buffer layer under the anodes to increase their work function (WF), and enhance hole transport across the organic/electrode interface. [11][12][13][14][15][16][17] The energy level alignment has been extensively argued in many reports; [18][19][20][21][22] several models have been proposed to understand their interfacial electronic structures. The electrostatic model based on the density of states in the organic semiconductor predicted the band-bending in organic semiconductors for different work functions.…”

Section: Doi: 101002/aelm201700136mentioning

confidence: 99%

Relation between Interfacial Band‐Bending and Electronic Properties in Organic Semiconductor Pentacene

Zhang

Zhao

Wang

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

carriers transport across the organic/electrode interface, such as charge injection in organic thin-film transistors and organic light-emission diodes, and carrier extraction in organic photovoltaic cells. Metal oxides were used as buffer layer under the anodes to increase their work function (WF), and enhance hole transport across the organic/electrode interface. [11][12][13][14][15][16][17] The energy level alignment has been extensively argued in many reports; [18][19][20][21][22] several models have been proposed to understand their interfacial electronic structures. The electrostatic model based on the density of states in the organic semiconductor predicted the band-bending in organic semiconductors for different work functions. [23,24] So far, most of the organic electronic devices still depend on the intrinsic properties of organic materials, and the interfacial electronic structures have not been vastly employed to realize the function of semiconductor devices. Therefore, it still remains a challenge for the effective tailoring of interfacial electronic structures to achieve the desired electronic properties in real electronic devices. Here, we demonstrated that the band-bending in organic semiconductors can be tuned by using the substrates with different work functions, and different interfacial structures leaded to various electronic transport properties. The works are promising exploration to realize the function of semiconductor devices by tailoring the desired interfacial electronic structures.We selected typical organic semiconductor pentacene to investigate the interfacial band-bending, and substrates were selected from high work function to low work function, i.e., PEDOT:PSS/ITO (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/indium tin oxide) of 5.4 eV work function, ITO of 4.1 eV, and PbO/ITO of 3.5 eV. The pentacene/ITO interface was first studied by using the in situ ultraviolet photoelectron spectroscopy (UPS), which is very effective and a direct tool to investigate interfacial electronic structures. Figure 1a gives the molecular structures of pentacene, and Figure 1b shows the UPS spectra of different pentacene coverage on ITO substrate, left panel is the secondary electron cut-off, which represents the work function of the film, and right panel is the valenceband photoelectron spectra in which the onset of first peak represents the highest occupied molecular orbital (HOMO). The work function of ITO is determined as 4.1 eV, which is about 0.9 eV above the HOMO of pentacene. From UPS and inverse photoelectron spectroscopy, [25]

show abstract

Section: Doi: 101002/aelm201700136mentioning

confidence: 99%

Relation between Interfacial Band‐Bending and Electronic Properties in Organic Semiconductor Pentacene

Zhang

Zhao

Wang

et al. 2017

Adv Elect Materials

View full text Add to dashboard Cite

show abstract

“…17,18 Specifically molybdenum trioxide ͑MoO 3 ͒ has proven to be an attractive material and has been used as a HIL in organic LEDs based on small molecules, [19][20][21][22] as buffer layer in organic solar cells 23,24 and as connecting layer in tandem organic LEDs. 25 The working mechanism of MoO 3 as HIL is generally ascribed to the formation of an interfacial dipole and consequently a reduction of the injection barrier.…”

mentioning

confidence: 99%

Space-charge-limited hole current in poly(9,9-dioctylfluorene) diodes

Nicolai

Wetzelaer

Kuik

et al. 2010

Applied Physics Letters

View full text Add to dashboard Cite

Characterization of the hole transport in blue-emitting polymers as poly(9,9-dioctylfluorene) (PFO) is strongly hindered by their large ionization potential of ∼6 eV. Using common anodes as poly(3,4-ethylenedioxythiophene)/poly(styrenesulphonic acid) leads to a strongly injection limited current. We demonstrate that molybdenum trioxide forms an Ohmic hole contact on PFO, enabling the observation of a space-charge-limited current(SCLC). This allows a direct determination of the hole mobility PFO of 1.3×10−9 m2/V s at room temperature, in good agreement with previously reported mobility values determined by time-of-flight measurements.

show abstract

“…However, the interface between ITO and PEDOT:PSS is not stable and the chemical reaction between ITO and PEDOT can result in degraded device performance [33]. Several metal oxides have been demonstrated as efficient hole injection materials for organic electroluminescent devices [34]. Here transition metal oxides, V 2 O 5 and MoO 3 , are demonstrated to effectively substitute PEDOT:PSS as the buffer layer in polymer PV cells [35], which makes high performance transparent solar cells feasible.…”

Section: Transition Metal Oxides As Hole Buffer Layers In Organic Phomentioning

confidence: 99%

Transparent Solar Cells Based on Organic Polymers

Huang¹,

Li²,

Li³

et al. 2010

Transparent Electronics

View full text Add to dashboard Cite

Organic electronics carry several prominent advantages over inorganic semiconductors, including light weight, flexibility, low cost, being environmentally friendly and transparent. After two decades of development, organic light emitting diode (OLED) [1] devices have started to be an industry [2]. Polymer solar cell (PSC) research has achieved several breakthroughs [3][4][5][6] in the first few years of the 21st century. These fast improvements in performance have distinguished this technology as a promising costeffective alternative or complimentary technology to inorganic solar cells. The regioregular poly(3-hexylthiophene) (RR-P3HT) [7,8] and [6,6]-phenyl C 60 butyric acid methyl ester (PCBM) [9] bulk heterojunction (BHJ) structure [10, 11] is a representative system for high efficiency PSCs [4][5][6]. While an external quantum efficiency (EQE) of over 70% [4-6, 12, 13] has been achieved in these PSCs, approaching that of their inorganic semiconductor counterparts, limited absorption in the solar spectrum remains a major limitation to achieving high efficiency. For example, only $ 40% of the solar energy is in the wavelength range shorter than 650 nm -the cut-off wavelength of RR-P3HT. While pursuing high efficiency is important, PSCs can provide other useful applications with their intrinsic properties like flexibility and transparency. Transparent or more precisely translucent solar cells could transfer the disadvantages of PSCs into advantages and will enable energy generation in various applications such as window and portable electronics. In addition, transparent solar cells provide an approach to further enhance PSC efficiency.

show abstract

Novel Electrodes from Solution-Processed Layer-Structure Materials

Cited by 60 publications

References 22 publications

Relation between Interfacial Band‐Bending and Electronic Properties in Organic Semiconductor Pentacene

Relation between Interfacial Band‐Bending and Electronic Properties in Organic Semiconductor Pentacene

Space-charge-limited hole current in poly(9,9-dioctylfluorene) diodes

Transparent Solar Cells Based on Organic Polymers

Contact Info

Product

Resources

About