Understanding of the aging pattern in quantum dot light-emitting diodes using low-frequency noise

Lee, Kook Jin; Yun, Jae-Yul; Lee, Suhyeon; Song, Jaeick; Kim, Yeonsu; Kwak, Jeonghun; Kim, Gyu Tae

doi:10.1039/d0nr01885f

Cited by 13 publications

(11 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar mechanism was also studied in another work by Lee et al, where positive aging was found to control the trap states and the exciton quenching at the ETL/EML interface. [ 103 ]…”

Section: Modification Methods For Zno‐based Electron Transport Layer ...mentioning

confidence: 99%

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Zanjani

Tintori

Sadeghi

et al. 2022

Advanced Photonics Research

View full text Add to dashboard Cite

Recent improvements in efficiency and luminance of quantum-dot light-emitting diodes (QLEDs) promise a versatile technology for next-generation lighting and display applications. This is accomplished due to the advances in colloidal quantum-dot (CQD) synthetic methods together with proper engineering of the charge balance in these devices. The exciton quenching mechanisms occurring at the interface between the QD emissive layer and the zinc oxide (ZnO) electron transport layer (ETL) are one of the important parts of the charge transport path, affecting efficiency and long-term stability. Herein, a comprehensive overview of the advances in the engineering of ZnO-based ETLs, in terms of device efficiency and operational stability, is attempted. It is specifically highlighted that significant improvements can be achieved using various ZnO ETL defect passivation methods. This review also describes the key requirements for high-performance QLEDs from the ETL engineering aspect and catalyzes for further interdisciplinary explorations to realize reliable devices for practical applications.

show abstract

“…A similar mechanism was also studied in another work by Lee et al, where positive aging was found to control the trap states and the exciton quenching at the ETL/EML interface. [ 103 ]…”

Section: Modification Methods For Zno‐based Electron Transport Layer ...mentioning

confidence: 99%

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Zanjani

Tintori

Sadeghi

et al. 2022

Advanced Photonics Research

View full text Add to dashboard Cite

show abstract

“…Time-dependent current measurement and low-frequency (LF) noise measurement are nondestructive and efficient analysis techniques to identify trapping/detrapping phenomena of carriers. [28,[41][42][43][44][45][46][47][48] The measurements for time-dependent current and LF noise were performed to further understand the phenomena of interaction of top and bottom conduction paths in the h-BN dual-gated ReS 2 channel. Specific V BG and V TG voltages were applied to the device with V D = 1 V, and the current fluctuations (ΔI D ) as a function of time, which were amplified by a current amplifier, were measured for 1 s with a sampling rate of 30 µs.…”

Section: Time-dependent Current and Low-frequency Noise Analysismentioning

confidence: 99%

Modeling and Understanding the Compact Performance of h‐BN Dual‐Gated ReS₂ Transistor

Lee

Choi

Kaczer

et al. 2021

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

In this study, high‐performance few‐layered ReS2 field‐effect transistors (FETs), fabricated with hexagonal boron nitride (h‐BN) as top/bottom dual gate dielectrics, are presented. The performance of h‐BN dual gated ReS2 FET having a trade‐off of performance parameters is optimized using a compact model from analytical choice maps, which consists of three regions with different electrical characteristics. The bottom h‐BN dielectric has almost no defects and provides a physical distance between the traps in the SiO2 and the carriers in the ReS2 channel. Using a compact analyzing model and structural advantages, an excellent and optimized performance is introduced consisting of h‐BN dual‐gated ReS2 with a high mobility of 46.1 cm2 V−1 s−1, a high current on/off ratio of ≈106, a subthreshold swing of 2.7 V dec−1, and a low effective interface trap density (Nt,eff) of 7.85 × 1010 cm−2 eV−1 at a small operating voltage (<3 V). These phenomena are demonstrated through not only a fundamental current–voltage analysis, but also technology computer aided design simulations, time‐dependent current, and low‐frequency noise analysis. In addition, a simple method is introduced to extract the interlayer resistance of ReS2 channel through Y‐function method as a function of constant top gate bias.

show abstract

“…Through numerous efforts on engineering of materials and devices, different types of high performance QLEDs were days in this year, Kim and co-workers reported humps in the capacitance-voltage characteristics of QLEDs and attributed these characteristics to the imbalanced carrier injections. [22] However, the impedance spectroscopy technique has not been fully exploited, and the relevant data has not been thoroughly analyzed. In this work, we clearly demonstrated there were negative charges accumulated in the thin films composed of CdSe/ZnS QDs (from Mesolight Nanotech Co., Ltd.) by conducting impedance spectroscopy on working QLEDs.…”

Section: Introductionmentioning

confidence: 99%

Identifying the Surface Charges and their Impact on Carrier Dynamics in Quantum‐Dot Light‐Emitting Diodes by Impedance Spectroscopy

Liu

et al. 2021

Advanced Optical Materials

View full text Add to dashboard Cite

The carrier injection and charge transfer at interfaces in quantum dot light‐emitting diodes (QLEDs) are commonly evaluated based on the energy levels of different functional layers. However, the actual charge dynamics in the experiments are found to be very different from the common expectations. In this work, QLEDs using 2,2′′,2′′′‐(1,3,5‐Benzinetriyl)‐tris(1‐phenyl‐1‐H‐benzimidazole) (TPBi) or zinc oxide (ZnO) nanoparticles as electron transport layer (ETL) are studied by impedance spectroscopy. It was the first time to observe that the hole injection and electron injection start at different applied bias. In QLEDs with TPBi ETL, at an applied bias as low as 0.5 V, large amounts of holes have injected into the hole transport layer, while electron injection only occurs after the applied bias increased up to about 3.0 V. This is caused by the intrinsic accumulated negative charges in the quantum dot (QD) layer. The adverse impacts of the negative accumulated charges in QD layer are mitigated by replacing TPBi with ZnO. Hole injection and electron injection start at the same applied bias, or 1.7 V if ZnO replaces TPBi. Charge transfer and neutralization processes between QD and ZnO layers are adopted to explain the above results.

show abstract

Understanding of the aging pattern in quantum dot light-emitting diodes using low-frequency noise

Abstract: The negative and positive aging effects of quantum dot (QD) light-emitting diodes (QLEDs) have received considerable attention in recent years and various analysis methods have been discussed. Here, we introduce...

Cited by 13 publications

References 33 publications

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Modeling and Understanding the Compact Performance of h‐BN Dual‐Gated ReS₂ Transistor

Identifying the Surface Charges and their Impact on Carrier Dynamics in Quantum‐Dot Light‐Emitting Diodes by Impedance Spectroscopy

Contact Info

Product

Resources

About

Understanding of the aging pattern in quantum dot light-emitting diodes using low-frequency noise

Abstract: The negative and positive aging effects of quantum dot (QD) light-emitting diodes (QLEDs) have received considerable attention in recent years and various analysis methods have been discussed. Here, we introduce...

Cited by 13 publications

References 33 publications

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Tailored ZnO Functional Nanomaterials for Solution‐Processed Quantum‐Dot Light‐Emitting Diodes

Modeling and Understanding the Compact Performance of h‐BN Dual‐Gated ReS2 Transistor

Identifying the Surface Charges and their Impact on Carrier Dynamics in Quantum‐Dot Light‐Emitting Diodes by Impedance Spectroscopy

Contact Info

Product

Resources

About

Modeling and Understanding the Compact Performance of h‐BN Dual‐Gated ReS₂ Transistor