Submit to Electronics Review for Electronics Propose a Special Issue

Journal Browser

► Journal Browser

Organic Semiconductors

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Electronics (ISSN 2079-9292). This special issue belongs to the section "Microelectronics".

Deadline for manuscript submissions: closed (15 January 2014) | Viewed by 168536

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special issue Organic Semiconductors book cover image

Share This Special Issue

Special Issue Editor

Prof. Dr. Mohan Jacob

E-Mail Website
Guest Editor

Electronic Materials Research Lab, College of Science and Engineering, Technology and Engineering, James Cook University, Townsville, QLD 4811, Australia
Interests: polymer thin films; plasma polymerisation; biocompatibility; biotechnology; biofouling; electronic materials; organic semiconductors; microwave characterisation of superconductors and dielectric materials
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Organic Semiconductors: Past, Present and Future

Over the last few years Organic Semiconducting industry showed significant growth in many areas dominated by conventional electronics. The foremost advantage of organic materials is that they are cheap, lightweight and flexible. In addition, the fabrication of organic materials from a defined molecular precursor using inkjet−printing technology is simple, bypassing the need for advanced semiconductor processing techniques. Organic thin films have already found confirmed and reliable applications in flexible displays, solar cells and biomedical applications, including implantable devices. Low cost materials, compatible with current organic electronic fabrication techniques and which improve device performance are in strong demand.

This special issue of Organic Semiconductors will cover Materials, Fabrication Techniques, Characterization, Devices and market adoption of Organic Semiconductors. This special issue will publish both original research papers and review papers in the field of research.

Dr. Mohan Jacob
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Electronics is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

organic field effect transistors
organic light emitting diodes
organic solar cells
implantable devices
biomaterials
flexible electronics
charge transport
charge transporting materials

Published Papers (14 papers)

Download All Papers

Editorial

Jump to: Research, Review

164 KiB

Open AccessEditorial

Organic Semiconductors: Past, Present and Future

by Mohan V. Jacob

Electronics 2014, 3(4), 594-597; https://doi.org/10.3390/electronics3040594 - 30 Sep 2014

Cited by 31 | Viewed by 7749

Abstract

Organic electronics, such as displays, photovoltaics and electronics circuits and components, offer several advantages over the conventional inorganic-based electronics because they are inexpensive, flexible, unbreakable, optically transparent, lightweight and have low power consumption. In particular, organic displays exhibit high brightness, fast response time, [...] Read more.

(This article belongs to the Special Issue Organic Semiconductors)

Research

Jump to: Editorial, Review

947 KiB

Open AccessArticle

Strong Coupling between Plasmons and Organic Semiconductors

by Joel Bellessa, Clementine Symonds, Julien Laverdant, Jean-Michel Benoit, Jean Claude Plenet and Stephane Vignoli

Electronics 2014, 3(2), 303-313; https://doi.org/10.3390/electronics3020303 - 06 May 2014

Cited by 25 | Viewed by 9166

Abstract

In this paper we describe the properties of organic material in strong coupling with plasmon, mainly based on our work in this field of research. The strong coupling modifies the optical transitions of the structure, and occurs when the interaction between molecules and plasmon prevails on the damping of the system. We describe the dispersion relation of different plasmonic systems, delocalized and localized plasmon, coupled to aggregated dyes and the typical properties of these systems in strong coupling. The modification of the dye emission is also studied. In the second part, the effect of the microscopic structure of the organics, which can be seen as a disordered film, is described. As the different molecules couple to the same plasmon mode, an extended coherent state on several microns is observed. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

986 KiB

Open AccessArticle

Optical and Surface Characterization of Radio Frequency Plasma Polymerized 1-Isopropyl-4-Methyl-1,4-Cyclohexadiene Thin Films

by Jakaria Ahmad, Kateryna Bazaka and Mohan V. Jacob

Electronics 2014, 3(2), 266-281; https://doi.org/10.3390/electronics3020266 - 23 Apr 2014

Cited by 36 | Viewed by 8246

Abstract

Low pressure radio frequency plasma-assisted deposition of 1-isopropyl-4-methyl-1,4-cyclohexadiene thin films was investigated for different polymerization conditions. Transparent, environmentally stable and flexible, these organic films are promising candidates for organic photovoltaics (OPV) and flexible electronics applications, where they can be used as encapsulating coatings and insulating interlayers. The effect of deposition RF power on optical properties of the films was limited, with all films being optically transparent, with refractive indices in a range of 1.57–1.58 at 500 nm. The optical band gap (E_g) of ~3 eV fell into the insulating E_g region, decreasing for films fabricated at higher RF power. Independent of deposition conditions, the surfaces were smooth and defect-free, with uniformly distributed morphological features and average roughness between 0.30 nm (at 10 W) and 0.21 nm (at 75 W). Films fabricated at higher deposition power displayed enhanced resistance to delamination and wear, and improved hardness, from 0.40 GPa for 10 W to 0.58 GPa for 75 W at a load of 700 μN. From an application perspective, it is therefore possible to tune the mechanical and morphological properties of these films without compromising their optical transparency or insulating property. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

255 KiB

Open AccessArticle

Improvement in the Lifetime of Planar Organic Photovoltaic Cells through the Introduction of MoO₃ into Their Cathode Buffer Layers

by Linda Cattin, Mustapha Morsli and Jean Christian Bernède

Electronics 2014, 3(1), 122-131; https://doi.org/10.3390/electronics3010122 - 06 Mar 2014

Cited by 9 | Viewed by 7832

Abstract

Recently, MoO₃, which is typically used as an anode buffer layer in organic photovoltaic cells (OPVCs), has also been used as a cathode buffer layer (CBL). Here, we check its efficiency as a CBL using a planar heterojunction based on the CuPc/C₆₀ couple. The CBL is a bi-layer tris-(8-hydroxyquinoline) aluminum (Alq₃)/MoO₃. We show that the OPVC with MoO₃ in its CBL almost immediately exhibits lower efficiency than those using Alq₃ alone. Nevertheless, the OPVCs increase their efficiency during the first five to six days of air exposure. We explain this evolution of the efficiency of the OPVCs over time through the variation in the MoO₃ work function due to air contamination. By comparison to a classical OPVC using a CBL containing only Alq₃, if it is found that the initial efficiency of the latter is higher, this result is no longer the same after one week of exposure to ambient air. Indeed, this result is due to the fact that the lifetime of the cells is significantly increased by the presence of MoO₃ in the CBL. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Graphical abstract

747 KiB

Open AccessArticle

Effects of Germanium Tetrabromide Addition to Zinc Tetraphenyl Porphyrin / Fullerene Bulk Heterojunction Solar Cells

by Atsushi Suzuki, Kenta Nishimura and Takeo Oku

Electronics 2014, 3(1), 112-121; https://doi.org/10.3390/electronics3010112 - 04 Mar 2014

Cited by 8 | Viewed by 7602

Abstract

The effects of germanium tetrabromide addition to tetraphenyl porphyrin zinc (Zn-TPP)/fullerene (C₆₀) bulk heterojunction solar cells were characterized. The light-induced charge separation and charge transfer were investigated by current density and optical absorption. Addition of germanium tetrabromide inserted into active layer of Zn-TPP/C₆₀ as bulk heterojunction had a positive effect on the photovoltaic and optical properties. The photovoltaic mechanism of the solar cells was discussed by experimental results. The photovoltaic performance was due to light-induced exciton promoted by insert of GeBr₄ and charge transfer from HOMO of Zn-TPP to LUMO of C₆₀ in the active layer. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

456 KiB

Open AccessArticle

Morphology, Electrical Performance and Potentiometry of PDIF-CN₂ Thin-Film Transistors on HMDS-Treated and Bare Silicon Dioxide

by Fabio Chiarella, Mario Barra, Laura Ricciotti, Alberto Aloisio and Antonio Cassinese

Electronics 2014, 3(1), 76-86; https://doi.org/10.3390/electronics3010076 - 24 Feb 2014

Cited by 23 | Viewed by 8315

Abstract

In this work, the electrical response of n-type organic field-effect transistors, achieved by evaporating PDIF-CN₂ films on both bare and Hexamethyldisilazane (HMDS) treated SiO₂ substrates, was investigated by standard electrical characterization and potentiometry. Morphological and charge transport characterizations demonstrated that the hydrophobic degree of the substrate surface has a huge impact on the final response of the devices. The PDIF-CN₂ transistors on HMDS-treated substrates show a maximum mobility of 0.7 cm²/Volt·s, three orders of magnitude greater than in the case of the device without surface functionalization. The scanning Kelvin probe microscopy technique was used to perform surface potentiometry to image the local surface potential inside the channel during the transistor operation and has allowed us to identify the film morphological disorder as the primary factor that could compromise the effectiveness of the charge injection process from gold contacts to PDIF-CN₂ films. For optimized devices on HMDS-treated substrates, SKPM was also used to analyze, over time, the evolution of the potential profile when negative V_GS voltages were applied. The findings of these measurements are discussed taking into account the role of V_GS-induced proton migration towards SiO₂ bulk, in the operational stability of the device. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

Review

Jump to: Editorial, Research

6495 KiB

Open AccessReview

Bio-Organic Electronics—Overview and Prospects for the Future

by Susan Mühl and Beatrice Beyer

Electronics 2014, 3(3), 444-461; https://doi.org/10.3390/electronics3030444 - 18 Jul 2014

Cited by 54 | Viewed by 13346

Abstract

In recent years, both biodegradable and bio-based electronics have attracted increasing interest, but are also controversially discussed at the same time. Yet, it is not clear whether they will contribute to science and technology or whether they will disappear without major impact. The present review will address several aspects while showing the potential opportunities of bio-organic electronics. An overview about the complex terminology of this emerging field is given and test methods are presented which are used to evaluate the biodegradable properties. It will be shown that the majority of components of organic electronics can be substituted by biodegradable or bio-based materials. Moreover, application scenarios are presented where bio-organic materials have advantages compared to conventional ones. A variety of publications are highlighted which encompass typical organic devices like organic light emitting diodes, organic solar cells and organic thin film transistors as well as applications in the field of medicine or agriculture. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Graphical abstract

966 KiB

Open AccessReview

Bandgap Science for Organic Solar Cells

by Masahiro Hiramoto, Masayuki Kubo, Yusuke Shinmura, Norihiro Ishiyama, Toshihiko Kaji, Kazuya Sakai, Toshinobu Ohno and Masanobu Izaki

Electronics 2014, 3(2), 351-380; https://doi.org/10.3390/electronics3020351 - 11 Jun 2014

Cited by 45 | Viewed by 16522

Abstract

The concept of bandgap science of organic semiconductor films for use in photovoltaic cells, namely, high-purification, pn-control by doping, and design of the built-in potential based on precisely-evaluated doping parameters, is summarized. The principle characteristics of organic solar cells, namely, the exciton, donor (D)/acceptor (A) sensitization, and p-i-n cells containing co-deposited and D/A molecular blended i-interlayers, are explained. ‘Seven-nines’ (7N) purification, together with phase-separation/cystallization induced by co-evaporant 3^rd molecules allowed us to fabricate 5.3% efficient cells based on 1 µm-thick fullerene:phthalocyanine (C₆₀:H₂Pc) co-deposited films. pn-control techniques enabled by impurity doping for both single and co-deposited films were established. The carrier concentrations created by doping were determined by the Kelvin band mapping technique. The relatively high ionization efficiency of 10% for doped organic semiconductors can be explained by the formation of charge transfer (CT)-complexes between the dopants and the organic semiconductor molecules. A series of fundamental junctions, such as Schottky junctions, pn-homojunctions, p⁺, n⁺-organic/metal ohmic junctions, and n⁺-organic/ p⁺-organic ohmic homojunctions, were fabricated in both single and co-deposited organic semiconductor films by impurity doping alone. A tandem cell showing 2.4% efficiency was fabricated in which the built-in electric field was designed by manipulating the doping. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

693 KiB

Open AccessReview

Anomalous Response in Heteroacene-Based Organic Field Effect Transistors under High Pressure

by Ken-ichi Sakai and Jun Takeya

Electronics 2014, 3(2), 255-265; https://doi.org/10.3390/electronics3020255 - 10 Apr 2014

Cited by 3 | Viewed by 6811

Abstract

Carrier transport properties of organic field effect transistors in dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene single crystals have been investigated under high pressure. In contrast to the typical pressure effect of monotonic increase in charge transfer rates according to the application of external hydrostatic pressure, it is clarified that the present organic semiconductor devices exhibit nonmonotonic pressure response, such as negative pressure effect. X-ray diffraction analysis under high pressure reveals that on-site molecular orientation and displacement in the heteroacene molecule is assumed to be the origin for the anomalous pressure effects. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

827 KiB

Open AccessReview

Organic Thin-Film Transistor (OTFT)-Based Sensors

by Daniel Elkington, Nathan Cooling, Warwick Belcher, Paul C. Dastoor and Xiaojing Zhou

Electronics 2014, 3(2), 234-254; https://doi.org/10.3390/electronics3020234 - 08 Apr 2014

Cited by 94 | Viewed by 24287

Abstract

Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

2674 KiB

Open AccessReview

Emerging Transparent Conducting Electrodes for Organic Light Emitting Diodes

by Tze-Bin Song and Ning Li

Electronics 2014, 3(1), 190-204; https://doi.org/10.3390/electronics3010190 - 21 Mar 2014

Cited by 50 | Viewed by 13841

Abstract

Organic light emitting diodes (OLEDs) have attracted much attention in recent years as next generation lighting and displays, due to their many advantages, including superb performance, mechanical flexibility, ease of fabrication, chemical versatility, etc. In order to fully realize the highly flexible features, reduce the cost and further improve the performance of OLED devices, replacing the conventional indium tin oxide with better alternative transparent conducting electrodes (TCEs) is a crucial step. In this review, we focus on the emerging alternative TCE materials for OLED applications, including carbon nanotubes (CNTs), metallic nanowires, conductive polymers and graphene. These materials are selected, because they have been applied as transparent electrodes for OLED devices and achieved reasonably good performance or even higher device performance than that of indium tin oxide (ITO) glass. Various electrode modification techniques and their effects on the device performance are presented. The effects of new TCEs on light extraction, device performance and reliability are discussed. Highly flexible, stretchable and efficient OLED devices are achieved based on these alternative TCEs. These results are summarized for each material. The advantages and current challenges of these TCE materials are also identified. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

421 KiB

Open AccessReview

The Effects of Different Electron-Phonon Couplings on the Spectral and Transport Properties of Small Molecule Single-Crystal Organic Semiconductors

by Carmine Antonio Perroni, Fernando Gargiulo, Alberto Nocera, Vincenzo Marigliano Ramaglia and Vittorio Cataudella

Electronics 2014, 3(1), 165-189; https://doi.org/10.3390/electronics3010165 - 21 Mar 2014

Cited by 6 | Viewed by 6720

Abstract

Spectral and transport properties of small molecule single-crystal organic semiconductors have been theoretically analyzed focusing on oligoacenes, in particular on the series from naphthalene to rubrene and pentacene, aiming to show that the inclusion of different electron-phonon couplings is of paramount importance to interpret accurately the properties of prototype organic semiconductors. While in the case of rubrene, the coupling between charge carriers and low frequency inter-molecular modes is sufficient for a satisfactory description of spectral and transport properties, the inclusion of electron coupling to both low-frequency inter-molecular and high-frequency intra-molecular vibrational modes is needed to account for the temperature dependence of transport properties in smaller oligoacenes. For rubrene, a very accurate analysis in the relevant experimental configuration has allowed for the clarification of the origin of the temperature-dependent mobility observed in these organic semiconductors. With increasing temperature, the chemical potential moves into the tail of the density of states corresponding to localized states, but this is not enough to drive the system into an insulating state. The mobility along different crystallographic directions has been calculated, including vertex corrections that give rise to a transport lifetime one order of magnitude smaller than the spectral lifetime of the states involved in the transport mechanism. The mobility always exhibits a power-law behavior as a function of temperature, in agreement with experiments in rubrene. In systems gated with polarizable dielectrics, the electron coupling to interface vibrational modes of the gate has to be included in addition to the intrinsic electron-phonon interaction. While the intrinsic bulk electron-phonon interaction affects the behavior of mobility in the coherent regime below room temperature, the coupling with interface modes is dominant for the activated high temperature contribution of localized polarons. Finally, the effects of a weak disorder largely increase the activation energies of mobility and induce the small polaron formation at lower values of electron-phonon couplings in the experimentally relevant temperature window. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

3458 KiB

Open AccessReview

Electron and Hole Transport Layers: Their Use in Inverted Bulk Heterojunction Polymer Solar Cells

by Sandro Lattante

Electronics 2014, 3(1), 132-164; https://doi.org/10.3390/electronics3010132 - 06 Mar 2014

Cited by 148 | Viewed by 19649

Abstract

Bulk heterojunction polymer solar cells (BHJ PSCs) are very promising organic-based devices for low-cost solar energy conversion, compatible with roll-to-roll or general printing methods for mass production. Nevertheless, to date, many issues should still be addressed, one of these being the poor stability in ambient conditions. One elegant way to overcome such an issue is the so-called “inverted” BHJ PSC, a device geometry in which the charge collection is reverted in comparison with the standard geometry device, i.e., the electrons are collected by the bottom electrode and the holes by the top electrode (in contact with air). This reverted geometry allows one to use a high work function top metal electrode, like silver or gold (thus avoiding its fast oxidation and degradation), and eliminates the need of a polymeric hole transport layer, typically of an acidic nature, on top of the transparent metal oxide bottom electrode. Moreover, this geometry is fully compatible with standard roll-to-roll manufacturing in air and is less demanding for a good post-production encapsulation process. To date, the external power conversion efficiencies of the inverted devices are generally comparable to their standard analogues, once both the electron transport layer and the hole transport layer are fully optimized for the particular device. Here, the most recent results on this particular optimization process will be reviewed, and a general outlook regarding the inverted BHJ PSC will be depicted. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Graphical abstract

1089 KiB

Open AccessReview

Integration of Organic Light Emitting Diodes and Organic Photodetectors for Lab-on-a-Chip Bio-Detection Systems

by Graeme Williams, Christopher Backhouse and Hany Aziz

Electronics 2014, 3(1), 43-75; https://doi.org/10.3390/electronics3010043 - 13 Feb 2014

Cited by 69 | Viewed by 16790

Abstract

The rapid development of microfluidics and lab-on-a-chip (LoC) technologies have allowed for the efficient separation and manipulation of various biomaterials, including many diagnostically relevant species. Organic electronics have similarly enjoyed a great deal of research, resulting in tiny, highly efficient, wavelength-selective organic light-emitting diodes (OLEDs) and organic photodetectors (OPDs). We consider the blend of these technologies for rapid detection and diagnosis of biological species. In the ideal system, optically active or fluorescently labelled biological species can be probed via light emission from OLEDs, and their subsequent light emission can be detected with OPDs. The relatively low cost and simple fabrication of the organic electronic devices suggests the possibility of disposable test arrays. Further, with full integration, the finalized system can be miniaturized and made simple to use. In this review, we consider the design constraints of OLEDs and OPDs required to achieve fully organic electronic optical bio-detection systems. Current approaches to integrated LoC optical sensing are first discussed. Fully realized OLED- and OPD-specific photoluminescence detection systems from literature are then examined, with a specific focus on their ultimate limits of detection. The review highlights the enormous potential in OLEDs and OPDs for integrated optical sensing, and notes the key avenues of research for cheap and powerful LoC bio-detection systems. Full article

(This article belongs to the Special Issue Organic Semiconductors)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Organic Semiconductors

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (14 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI