scholarly journals Large Area Emission in p-Type Polymer-Based Light-Emitting Field-Effect Transistors by Incorporating Charge Injection Interlayers

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 901
Author(s):  
Gizem Acar ◽  
Muhammad Javaid Iqbal ◽  
Mujeeb Ullah Chaudhry

Organic light-emitting field-effect transistors (LEFETs) provide the possibility of simplifying the display pixilation design as they integrate the drive-transistor and the light emission in a single architecture. However, in p-type LEFETs, simultaneously achieving higher external quantum efficiency (EQE) at higher brightness, larger and stable emission area, and high switching speed are the limiting factors for to realise their applications. Herein, we present a p-type polymer heterostructure-based LEFET architecture with electron and hole injection interlayers to improve the charge injection into the light-emitting layer, which leads to better recombination. This device structure provides access to hole mobility of ~2.1 cm2 V−1 s−1 and EQE of 1.6% at a luminance of 2600 cd m−2. Most importantly, we observed a large area emission under the entire drain electrode, which was spatially stable (emission area is not dependent on the gate voltage and current density). These results show an important advancement in polymer-based LEFET technology toward realizing new digital display applications.

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Muhammad Naqi ◽  
Kyung Hwan Choi ◽  
Hocheon Yoo ◽  
Sudong Chae ◽  
Bum Jun Kim ◽  
...  

AbstractLow-temperature-processed semiconductors are an emerging need for next-generation scalable electronics, and these semiconductors need to feature large-area fabrication, solution processability, high electrical performance, and wide spectral optical absorption properties. Although various strategies of low-temperature-processed n-type semiconductors have been achieved, the development of high-performance p-type semiconductors at low temperature is still limited. Here, we report a unique low-temperature-processed method to synthesize tellurium nanowire networks (Te-nanonets) over a scalable area for the fabrication of high-performance large-area p-type field-effect transistors (FETs) with uniform and stable electrical and optical properties. Maximum mobility of 4.7 cm2/Vs, an on/off current ratio of 1 × 104, and a maximum transconductance of 2.18 µS are achieved. To further demonstrate the applicability of the proposed semiconductor, the electrical performance of a Te-nanonet-based transistor array of 42 devices is also measured, revealing stable and uniform results. Finally, to broaden the applicability of p-type Te-nanonet-based FETs, optical measurements are demonstrated over a wide spectral range, revealing an exceptionally uniform optical performance.


2011 ◽  
Vol 15 (09n10) ◽  
pp. 964-972
Author(s):  
Ronghua Guo ◽  
Lijuan Zhang ◽  
Yuexing Zhang ◽  
Yongzhong Bian ◽  
Jianzhuang Jiang

Density functional theory (DFT) calculations were carried out to investigate the semiconductor performance of a series of phthalocyaninato zinc complexes, namely Zn[Pc(β-OCH3)8] (1), ZnPc (2), and Zn[Pc(β-COOCH3)8] (3) {[ Pc(β-OCH3)8]2- = dianion of 2,3,9,10,16,17,23,24-octamethoxyphthalocyanine; Pc2- = dianion of phthalocyanine; [ Pc(β-COOCH3)8]2- = dianion of 2,3,9,10,16,17,23,24-octamethoxycarbonylphthalocyanine} for organic field effect transistor (OFET). The effect of peripheral substituents on tuning the nature of phthalocyaninato zinc semiconductor has been clearly revealed. Introduction of eight weak electron-donating methoxy groups onto the peripheral positions of ZnPc (2) leads to a decrease in the hole injection barrier relative to Au electrode and an increase in the electron injection barrier, making compound 1 a better p-type semiconductor material in comparison with 2. In contrast, peripheral methoxycarbonyl substitution depresses the energy level of LUMO and thus induces an increase for the electron affinity (EA) value of ZnPc (2), resulting in the change of semiconductor nature from p-type for ZnPc (2) to n-type for Zn[Pc(β-COOCH3)8] (3) due to the improved electron injection ability. The calculated charge transfer mobility for hole is 1.05 cm2.V-1.s-1 for 1 and 5.33 cm2.V-1.s-1 for 2, while that for electron is 0.16 cm2.V-1.s-1 for 3. The present work should be helpful for designing and preparing novel phthalocyanine semiconductors in particular with good n-type OFET performance.


2008 ◽  
Vol 608 ◽  
pp. 159-179 ◽  
Author(s):  
Richard Friend

Organic materials have been developed to operate as the active semiconductor in a wide range of semiconductor devices, including light-emitting diodes, LEDs, field-effect transistors, FETs, and photovoltaic diodes, PVs. The ability to process these materials as thin films over large areas makes possible a range of applications, currently in displays, as LEDs and as active matrix FET arrays, and solar cells. This article reviews developments in semiconductor physics of these materials and in their application in semiconductor devices


2019 ◽  
Vol 9 (6) ◽  
pp. 1110 ◽  
Author(s):  
Xiao-Mei Zhang ◽  
Sian-Hong Tseng ◽  
Ming-Yen Lu

Two-dimensional (2D) MoS2 has recently become of interest for applications in broad range photodetection due to their tunable bandgap. In order to develop 2D MoS2 photodetectors with ultrafast response and high responsivity, up-scalable techniques for realizing controlled p-type doping in MoS2 is necessary. In this paper, we demonstrate a p-type multilayer MoS2 photodetector with selective-area doping using CHF3 plasma treatment. Microscopic and spectroscopic characterization techniques, including atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), are used to investigate the morphological and electrical modification of the p-type doped MoS2 surface after CHF3 plasma treatment. Back-gated p-type MoS2 field-effect transistors (FETs) are fabricated with an on/off current ratio in the order of 103 and a field-effect mobility of 65.2 cm2V−1s−1. They exhibit gate-modulated ultraviolet photodetection with a rapid response time of 37 ms. This study provides a promising approach for the development of mild plasma-doped MoS2 as a 2D material in post-silicon electronic and optoelectronic device applications.


2015 ◽  
Vol 1788 ◽  
pp. 13-18
Author(s):  
M. Brast ◽  
S. Axmann ◽  
M. Slawinski ◽  
M. Weingarten ◽  
F. Lindla ◽  
...  

ABSTRACTThe development of efficient large-area organic light emitting diodes (OLED) requires reliable and easily processable charge generation layers (CGL) with low excess voltage drop and high optical transparency. OVPD offers the advantage of a precise control of layer morphology, composition and thickness and is a powerful method for the deposition of advanced OLED designs. In this work, electrical doping of organic semiconductors using OVPD is investigated and applied to stacked OLED utilizing inorganic/organic CGL. The organic p-type dopant NDP-9 of Novaled GmbH is used for doping the hole transport material N,N‘-diphenyl-N,N‘-bis(1-naphthylphenyl)-1,1‘-biphenyl-4,4‘-diamine (α-NPD) in an AIXTRON OVPD tool. A doping concentration of 8 vol.% of NDP-9 in α-NPD is found optimal for hole injection as well as conductivity. This dopant concentration was employed in CGL with the structure: electron transport material/LiF/Al/α-NPD:8 vol.% NDP-9. External quantum efficiencies (EQE) of 15%, 35% and 50% and luminous efficiencies of 37 lm/W, 45 lm/W and 45 lm/W at 1000 cd/m2 are demonstrated for single, double- and triple-unit green phosphorescent OLED, respectively.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2662
Author(s):  
Julia Fidyk ◽  
Witold Waliszewski ◽  
Piotr Sleczkowski ◽  
Adam Kiersnowski ◽  
Wojciech Pisula ◽  
...  

Organic electronics became an attractive alternative for practical applications in complementary logic circuits due to the unique features of organic semiconductors such as solution processability and ease of large-area manufacturing. Bulk heterojunctions (BHJ), consisting of a blend of two organic semiconductors of different electronic affinities, allow fabrication of a broad range of devices such as light-emitting transistors, light-emitting diodes, photovoltaics, photodetectors, ambipolar transistors and sensors. In this work, the charge carrier transport of BHJ films in field-effect transistors is switched from electron to hole domination upon processing and post-treatment. Low molecular weight n-type N,N′-bis(n-octyl)-(1,7&1,6)-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN2) was blended with p-type poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene] (PBTTT-C14) and deposited by spin-coating to form BHJ films. Systematic investigation of the role of rotation speed, solution temperature, and thermal annealing on thin film morphology was performed using atomic force microscopy, scanning electron microscopy, and grazing incidence wide-angle X-ray scattering. It has been determined that upon thermal annealing the BHJ morphology is modified from small interconnected PDI8-CN2 crystals uniformly distributed in the polymer fraction to large planar PDI8-CN2 crystal domains on top of the blend film, leading to the switch from electron to hole transport in field-effect transistors.


2004 ◽  
Vol 814 ◽  
Author(s):  
Yifan Xu ◽  
Paul R. Berger ◽  
James N. Wilson ◽  
Uwe H.F. Bunz

The photoresponse of polymer field effect transistors (PFETs) based on the 2,5- bis(dibutylaminostyryl)-1,4-phenylene-b-alkyne-b-1,4-bis(2-ethylhexyl)benzene terpolymer (BAS-PPE) is investigated. BAS-PPE is a photoluminescent conducting polymer with a bandgap of 2.25 eV. The BAS-PPE PFETs were fabricated using an open coplanar configuration and light is illuminated onto the top side of the PFETs. A sweep of VDS demonstrates that IDS saturation is suppressed during illumination, which suggests that pinch-off can not be reached since the injection of photo-generated carriers continues unabated. Also, with incident light, the channel can not be turned off, even at high positive gate biases, due to the accumulation of photo- generated carriers. A sweep of VDS also shows that BAS-PPE can act as a p-type polymer and favors hole injection and transport.


2013 ◽  
Vol 14 (11) ◽  
pp. 2953-2961 ◽  
Author(s):  
Kristen Tandy ◽  
Mujeeb Ullah ◽  
Paul L. Burn ◽  
Paul Meredith ◽  
Ebinazar B. Namdas

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