All Outputs (37)

Singlet Fission and Triplet Exciton Dynamics in Rubrene/Fullerene Heterojunctions: Implications for Electroluminescence. (2015)
Journal Article
Ullah, M., Yambem, S. D., Moore, E. G., Namdas, E. B., & Pandey, A. K. (2015). Singlet Fission and Triplet Exciton Dynamics in Rubrene/Fullerene Heterojunctions: Implications for Electroluminescence. Advanced Electronic Materials, 1(12), Article 1500229. https://doi.org/10.1002/aelm.201500229

The role of triplet excitons in rubrene/C60 heterojunctions is investigated through detailed spectroscopic studies of triplet generation routes in the neat and heterojunction films of rubrene and C60. Time-correlated single-photon counting experiment... Read More about Singlet Fission and Triplet Exciton Dynamics in Rubrene/Fullerene Heterojunctions: Implications for Electroluminescence..

Hybrid Area-Emitting Transistors: Solution Processable and with High Aperture Ratios. (2015)
Journal Article
Muhieddine, K., Ullah, M., Maasoumi, F., Burn, P. L., & Namdas, E. B. (2015). Hybrid Area-Emitting Transistors: Solution Processable and with High Aperture Ratios. Advanced Materials, 27(42), 6677-6682. https://doi.org/10.1002/adma.201502554

Area emission is realized in all-solution-processed hybrid light-emitting transistors (HLETs). A new HLET design is presented with increased aperture ratio, and optical and electrical characteristics are shown.

Defining the light emitting area for displays in the unipolar regime of highly efficient light emitting transistors (2015)
Journal Article
Ullah, M., Armin, A., Tandy, K., Yambem, S. D., Burn, P. L., Meredith, P., & Namdas, E. B. (2015). Defining the light emitting area for displays in the unipolar regime of highly efficient light emitting transistors. Scientific Reports, 5, Article 8818. https://doi.org/10.1038/srep08818

Light-emitting field effect transistors (LEFETs) are an emerging class of multifunctional optoelectronic devices. It combines the light emitting function of an OLED with the switching function of a transistor in a single device architecture. The dual... Read More about Defining the light emitting area for displays in the unipolar regime of highly efficient light emitting transistors.

Efficient and bright polymer light emitting field effect transistors. (2014)
Journal Article
Ullah, M., Tandy, K., Yambem, S. D., Muhieddine, K., Ong, W. J., Shi, Z., …Namdas, E. B. (2015). Efficient and bright polymer light emitting field effect transistors. Organic Electronics, 17, 371-376. https://doi.org/10.1016/j.orgel.2014.12.014

Light emitting field effect transistors (LEFETs) are emerging as a multi-functional class of optoelectronic devices. LEFETs can simultaneously execute light emission and the standard logic functions of a transistor in a single architecture. However,... Read More about Efficient and bright polymer light emitting field effect transistors..

High-Performance, Solution-Processed Non-polymeric Organic Photodiodes (2014)
Journal Article
Kim, I. K., Pal, B. N., Ullah, M., Burn, P. L., Lo, S., Meredith, P., & Namdas, E. B. (2015). High-Performance, Solution-Processed Non-polymeric Organic Photodiodes. Advanced Optical Materials, 3(1), 50-56. https://doi.org/10.1002/adom.201400385

High-performance, solution-processed, non-polymeric broadband organic photo­diodes (OPDs) with a dark current density of 0.11 nA cm-2, responsivity of 0.4 A W-1, and detectivity of up to 9.2 × 1012 Jones are demonstrated.

High-Mobility, Heterostructure Light-Emitting Transistors and Complementary Inverters (2014)
Journal Article
Ullah, M., Tandy, K., Li, J., Shi, Z., Burn, P. L., Meredith, P., & Namdas, E. B. (2014). High-Mobility, Heterostructure Light-Emitting Transistors and Complementary Inverters. ACS Photonics, 1(10), 954-959. https://doi.org/10.1021/ph500300n

Light-emitting field effect transistors (LEFETs) are optoelectronic devices that can simultaneously execute light emission and the standard logic functions of a transistor in a single device architecture. In this article, we show that ambipolar LEFET... Read More about High-Mobility, Heterostructure Light-Emitting Transistors and Complementary Inverters.

All Solution-Processed, Hybrid Light Emitting Field-Effect Transistors (2014)
Journal Article
Muhieddine, K., Ullah, M., Pal, B. N., Burn, P., & Namdas, E. B. (2014). All Solution-Processed, Hybrid Light Emitting Field-Effect Transistors. Advanced Materials, 26(37), 6410-6415. https://doi.org/10.1002/adma.201400938

All solution-processed, high performance hybrid light emitting transistors (HLETs) are realized. Using a novel combination of device architecture and materials a bilayer device comprised of an inorganic and organic semiconducting layer is fabricated... Read More about All Solution-Processed, Hybrid Light Emitting Field-Effect Transistors.

Charge Transport in Organic Diodes and OFETs: A Comparison (2013)
Book Chapter
Ullah, M., Pivrikas, A., Sariciftci, N. S., & Sitter, H. (2013). Charge Transport in Organic Diodes and OFETs: A Comparison. In Small Organic Molecules on Surfaces. https://doi.org/10.1007/978-3-642-33848-9_8

ITO-free top emitting organic light emitting diodes with enhanced light out-coupling (2013)
Journal Article
Yambem, S. D., Ullah, M., Tandy, K., Burn, P. L., & Namdas, E. B. (2014). ITO-free top emitting organic light emitting diodes with enhanced light out-coupling. Laser and Photonics Reviews, 8(1), 165-171. https://doi.org/10.1002/lpor.201300148

Bottom emitting organic light emitting diodes (OLEDs) can suffer from lower external quantum efficiencies (EQE) due to inefficient out-coupling of the generated light. Herein, it is demonstrated that the current efficiency and EQE of red, yellow, and... Read More about ITO-free top emitting organic light emitting diodes with enhanced light out-coupling.

Simultaneous Enhancement of Brightness, Efficiency, and Switching in RGB Organic Light Emitting Transistors (2013)
Journal Article
Ullah, M., Tandy, K., Yambem, S. D., Aljada, M., Burn, P. L., Meredith, P., & Namdas, E. B. (2013). Simultaneous Enhancement of Brightness, Efficiency, and Switching in RGB Organic Light Emitting Transistors. Advanced Materials, 25(43), 6213-6218. https://doi.org/10.1002/adma.201302649

An innovative design strategy for light emitting field effect transistors (LEFETs) to harvest higher luminance and switching is presented. The strategy uses a non-planar electrode geometry in tri-layer LEFETs for simultaneous enhancement of the key p... Read More about Simultaneous Enhancement of Brightness, Efficiency, and Switching in RGB Organic Light Emitting Transistors.

Indigo - A Natural Pigment for High Performance Ambipolar Organic Field Effect Transistors and Circuits (2011)
Journal Article
Irimia-Vladu, M., Głowacki, E. D., Troshin, P. A., Schwabegger, G., Leonat, L., Susarova, D. K., …Sariciftci, N. S. (2012). Indigo - A Natural Pigment for High Performance Ambipolar Organic Field Effect Transistors and Circuits. Advanced Materials, 24(3), 375-380. https://doi.org/10.1002/adma.201102619

Millenniums-old natural dye indigo - a “new” ambipolar organic semiconductor. Indigo shows balanced electron and hole mobilities of 1 × 10−2 cm2 V−1 s−1 and good stability against degradation in air. Inverters with gains of 105 in the first and 110 i... Read More about Indigo - A Natural Pigment for High Performance Ambipolar Organic Field Effect Transistors and Circuits.

Effect of source-drain electric field on the Meyer–Neldel energy in organic field effect transistors (2011)
Journal Article
Ullah, M., Pivrikas, A., Fishchuk, I., Kadashchuk, A., Stadler, P., Simbrunner, C., …Sitter, H. (2011). Effect of source-drain electric field on the Meyer–Neldel energy in organic field effect transistors. Applied Physics Letters, 98(22), https://doi.org/10.1063/1.3584131

We studied the influence of the lateral source-drain electric field on the Meyer–Neldel phenomenon observed for the charge mobility measured in C60-based organic field effect transistors (OFETs). It was found that the characteristic Meyer-Neldel temp... Read More about Effect of source-drain electric field on the Meyer–Neldel energy in organic field effect transistors.

Electric field dependent activation energy of electron transport in fullerene diodes and field effect transistors: Gill’s law (2011)
Journal Article
Pivrikas, A., Ullah, M., Sitter, H., & Sariciftci, N. (2011). Electric field dependent activation energy of electron transport in fullerene diodes and field effect transistors: Gill’s law. Applied Physics Letters, 98(9), Article 092114. https://doi.org/10.1063/1.3557503

The electric field and temperature dependence of the electron mobility is studied comparatively in the bulk of fullerene (C60) diodes and at the interface with dielectric of organic field effect transistors (OFETs). Electron mobility values follow... Read More about Electric field dependent activation energy of electron transport in fullerene diodes and field effect transistors: Gill’s law.

Meyer–Neldel rule for charge carrier transport in fullerene devices: A comparative study (2010)
Journal Article
Pivrikas, A., Ullah, M., Singh, T., Simbrunner, C., Matt, G., Sitter, H., & Sariciftci, N. (2011). Meyer–Neldel rule for charge carrier transport in fullerene devices: A comparative study. Organic Electronics, 12(1), 161-168. https://doi.org/10.1016/j.orgel.2010.10.014

Charge transport is comparatively studied in the bulk and at the interface of disordered fullerene films fabricated using physical vapour deposition. Charge carrier concentration and temperature dependent electron mobilities are comparatively studied... Read More about Meyer–Neldel rule for charge carrier transport in fullerene devices: A comparative study.

Environmentally sustainable organic field effect transistors (2010)
Journal Article
Irimia-Vladu, M., Troshin, P. A., Reisinger, M., Schwabegger, G., Ullah, M., Schwoediauer, R., …Razumov, V. F. (2010). Environmentally sustainable organic field effect transistors. Organic Electronics, 11(12), 1974-1990. https://doi.org/10.1016/j.orgel.2010.09.007

Environmentally sustainable systems for the design, production, and handling of electronic devices should be developed to solve the dramatic increase in electronic waste. Sustainability in plastic electronics may be the production of electronic devic... Read More about Environmentally sustainable organic field effect transistors.

Temperature dependence of the charge carrier mobility in disordered organic semiconductors at large carrier concentrations (2010)
Journal Article
Fishchuk, I., Kadashchuk, A., Genoe, J., Ullah, M., Sitter, H., Singh, T. B., …Bässler, H. (2010). Temperature dependence of the charge carrier mobility in disordered organic semiconductors at large carrier concentrations. Physical review B, 81(4), Article 045202. https://doi.org/10.1103/physrevb.81.045202

Temperature-activated charge transport in disordered organic semiconductors at large carrier concentrations, especially relevant in organic field-effect transistors (OFETs), has been thoroughly considered using a recently developed analytical formali... Read More about Temperature dependence of the charge carrier mobility in disordered organic semiconductors at large carrier concentrations.

Electrical response of highly ordered organic thin film metal-insulator-semiconductor devices (2009)
Journal Article
Ullah, M., Taylor, D., Schwödiauer, R., Sitter, H., Bauer, S., Sariciftci, N., & Singh, T. B. (2009). Electrical response of highly ordered organic thin film metal-insulator-semiconductor devices. Journal of Applied Physics, 106(11), Article 114505. https://doi.org/10.1063/1.3267045

We report a detailed investigation of the electrical properties of organic field-effect transistors (OFETs) and metal-insulator-semiconductor (MIS) capacitors formed from highly ordered thin films of C60C60 as the active semiconductor and divinyltetr... Read More about Electrical response of highly ordered organic thin film metal-insulator-semiconductor devices.