scholarly journals The Rational Control of Precursor Concentration in Perovskite Light-Emitting Diodes

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 60
Author(s):  
Keke Song ◽  
Xiaoping Zou ◽  
Huiyin Zhang ◽  
Jin Cheng ◽  
Chunqian Zhang ◽  
...  

Perovskite light-emitting diodes (PeLEDs) have attracted tremendous attention due to their ideal optoelectronic properties, such as high color purity, high fluorescence quantum yield, and tunable light color. The perovskite layer plays a decisive role in the performance of PeLEDs and the solvent engineering of the perovskite layer is the key technological breakthrough in preparing high quality films. In this study, we have proposed the strategy of adding different amounts of solvents to the perovskite precursor solution to optimize the morphology of perovskite films and device performance. As a result, with the decreasing concentration of perovskite precursor solution, the perovskite film morphology is smoother and more favorable for carrier injection and combing, which induces an enhanced external quantum efficiency. The maximum luminance of PeLEDs was increased from 1667 cd/m2 to 9857 cd/m2 and the maximum current efficiency was increased from 6.7 cd/A to 19 cd/A. This work provides a trend to achieve improved film morphology and device performance for perovskite optoelectronic devices.

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 993
Author(s):  
Chen-Min Yang ◽  
Fang-Chung Chen

Metal nanoparticles have been widely used for improving the efficiencies of many optoelectronic devices. Herein, position effects of gold nanoparticles (Au NPs) on the performance of perovskite light-emitting diodes (PeLEDs) are investigated. Amphiphilic Au NPs are synthesized so that they can be incorporated into different layers of the PeLEDs to enhance device efficiencies. The photoluminescent (PL) studies indicate apparent position effects; the strongest PL intensity occurs when the NPs are directly blended with the light-emitting perovskite layer. In contrast, the PeLEDs exhibit the highest luminance efficiency while the Au NPs are placed in the hole-transporting layer. The direct blending of the NPs in the perovskite layer might affect the electrical properties, resulting in inferior device performance. The results reported herein can help to understand the enhancing mechanism of the PeLEDs and may also lead to even better efficiencies in the near future.


Nanoscale ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 1505-1514 ◽  
Author(s):  
Jae Choul Yu ◽  
Jong Hyun Park ◽  
Sang Yun Lee ◽  
Myoung Hoon Song

The device performance and long-term stability of perovskite light-emitting diodes (PeLEDs) can be improved by morphological control of perovskite films such as film modification, interface engineering, and quasi 2D.


2000 ◽  
Vol 660 ◽  
Author(s):  
Thomas M. Brown ◽  
Ian S. Millard ◽  
David J. Lacey ◽  
Jeremy H. Burroughes ◽  
Richard H. Friend ◽  
...  

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chuangchuang Chang ◽  
Xiaoping Zou ◽  
Jin Cheng ◽  
Ying Yang ◽  
Yujun Yao ◽  
...  

Perovskite solar cells (PSCs) have been developed rapidly in recent years. How to modify the photophysical properties of perovskite films has become the critical issue, affecting device performance. In this paper, NaI doping into the perovskite layer is attempted to modulate the photophysical properties to improve the performance of PSCs. The perovskite layer was prepared by using the one-step solution spin coating method with doping different concentrations of NaI into the perovskite precursor solution and chlorobenzene employed as the antisolvent. Experimental results show that the absorption band edge and the peak position of the PL spectrum of the doped perovskite thin film were red shifted; thus, the band gap of the semiconductor film became narrow. Doping NaI into perovskite is an effective way, by which the photophysical properties of perovskite films are well modified, thus improving device performance.


Author(s):  
Wenjing Feng ◽  
Kebin Lin ◽  
Wenqiang Li ◽  
Xiangtian Xiao ◽  
Jianxun Lu ◽  
...  

Metal halide perovskite light-emitting diodes (PeLEDs) are promising in lighting and display application, and the corresponding device performance is highly dependent on the film quality of the active layer. However,...


2012 ◽  
Vol 65 (9) ◽  
pp. 1244 ◽  
Author(s):  
Prashant Sonar ◽  
Sonsoles Garcia Santamaria ◽  
Ting Ting Lin ◽  
Alan Sellinger ◽  
Henk Bolink

The synthesis and characterisation of 2,5-bis(5′-hexyl-[2,2′-bithiophen]-5-yl)pyridine (Th4PY) and its use as a blue emitter in organic light emitting diodes (OLEDs) is reported. Th4PY was synthesised in high yield using a straightforward Suzuki coupling route with commercially available starting materials. As Th4PY is both soluble and has low molecular weight, blue OLEDs were fabricated using both spin-coating and vacuum deposition thin film processing techniques to study the effect of processing on device performance. OLED devices using a spin-coated layer consisting of 4′,4′′-tris(N-carbazolyl)triphenylamine (TCTA) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) as a host matrix together with Th4PY as emitter exhibited highly efficient sky-blue emission with a low turn-on voltage of 3 V, a maximum brightness close to 15000 cd m–2 at 8 V, and a maximum luminous efficiency of 7.4 cd A–1 (6.3 lm W–1) with CIE coordinates of x = 0.212, y = 0.320. The device performance characteristics are compared using various matrices and processing techniques. The promising sky-blue OLED performance, solution processability, and ambient stability make Th4PY a promising blue emitter for application in OLEDs.


2016 ◽  
Vol 10 (12) ◽  
pp. 782-787 ◽  
Author(s):  
T. H. Chung ◽  
G. Juska ◽  
S. T. Moroni ◽  
A. Pescaglini ◽  
A. Gocalinska ◽  
...  

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