Constant-Step-Stress Accelerated Life Test of White OLED Under Weibull Distribution Case

Zhang, Jianping; Zhou, Tingjun; Wu, Helen; Liu, Yu; Wu, Wen‐Li; Ren, Jianxing

doi:10.1109/ted.2011.2181175

Cited by 26 publications

(8 citation statements)

References 8 publications

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“…However, it gains more degradation information in one stress and is easy to extend to the case with more types of stress [11,12]. Thus, it has been applied widely in practice, for example, LEDs [11,12], OLEDs [30], and so forth. In the following, we incorporate the random effects into the CSADT and use the random Arrhenius model for an illustrative purpose.…”

Section: Random Acceleration Modelmentioning

confidence: 99%

Accelerated Degradation Tests Modeling Based on the Nonlinear Wiener Process with Random Effects

Tang

Guo

Chen

et al. 2014

Mathematical Problems in Engineering

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Accelerated degradation tests (ADT) modeling is an important issue in lifetime assessment to the products with high reliability and long lifetime. Among the literature about the accelerated nonlinear degradation process modeling, the current methods did not consider the product-to-product variation of the products with the same type. Therefore, this paper proposes an accelerated degradation process modeling method with random effects for the nonlinear Wiener process. Firstly, we derive the lifetime distribution of the nonlinear Wiener process with random effects. Secondly, the nonlinear Wiener process is used to model the degradation process of a single stress, and the drift coefficient is considered as a random variable to describe the product-to-product variation. Using the random acceleration model, the random effects are incorporated into the constant stress ADT models and the step stress ADT models. Then, a two-step maximum likelihood estimation (MLE) method is presented to estimate the unknown parameters in the degradation models. Finally, a simulation study and a case study are provided to demonstrate the application and superiority of the proposed model.

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Section: Random Acceleration Modelmentioning

confidence: 99%

Accelerated Degradation Tests Modeling Based on the Nonlinear Wiener Process with Random Effects

Tang

Guo

Chen

et al. 2014

Mathematical Problems in Engineering

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“…The origin of subthreshold turn-on in QLEDs is important for the discussion of many device physics problems. Sometimes the phenomenon is arguably linked with Auger-assisted energy up-conversion in which the extra energy is provided by the decay of charge-transfer (CT) excitons. , Such an effect requires at least two electron–hole pairs to generate one photon, and the device degradation is supposed to be accelerated exponentially according to the inverse power law . In the Auger process, the CT excitons can be formed with the injected holes and electrons accumulated across the type-II heterojunction interface. , In a QLED with multilayer structure, either the interface formed between the hole transporting layer (HTL) and emission layer (EML), or the one between EML and electron-transporting layer (ETL), is possible for the generation of CT excitons.…”

mentioning

confidence: 99%

Origin of Subthreshold Turn-On in Quantum-Dot Light-Emitting Diodes

Luo

Zhang

et al. 2019

ACS Nano

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The subthreshold (or sub-bandgap) turn-on for electroluminescence is one of the most discussed, but often misinterpreted, phenomena for solution-processed quantum-dot light-emitting diodes. Here, multiple techniques are applied to show that the phenomenon can be readily explained using the fundamental rules of carrier injection and transport. Evident from temperature dependent photovoltage measurements, it is found that the energy up-conversion originating from the decay of charge transfer excitons is not responsible for the subthreshold turn-on. Further analysis using electroabsorption reveals that the turn-on voltage of electroluminescence consistently correlates with the flat-band voltage of the emission layer. Under such subthreshold bias, although the device current is still limited by the depleted hole-transporting layer, field-assisted carrier injection starts to provide enough electrons and holes for detectable radiative recombination, thereby enabling distinct subthreshold turn-on.

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“…They used this model to characterize OLED panels. A Weibull distribution to model the OLEDs lifespan under constant step current density stresses was proposed in [18] and the same authors defined a lognormal distribution for the OLEDs lifetime under constant current density stress in [19]. OLED lifetime was also expressed as a Weibull function in [20].…”

Section: Existing Methods For Aging Modelingmentioning

confidence: 99%

Modeling the Luminance Degradation of OLEDs Using Design of Experiments

Salameh

Haddad

Picot

et al. 2019

IEEE Trans. on Ind. Applicat.

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Modeling the lifespan of OLED (Organic Light-Emitting Diode) is a complex task as it depends on differentpotentially interacting factors. As the literature on this subject is still scant, new parametric models for calculating the lifespan of OLED are proposed in this work. The Design of Experiment (DoE) methodology is used for cost and accuracy reasons. Different lifespan models based on thermal and electrical experimental aging tests are proposed. As stress factors, current density, temperature and their interactions, which are rarely taken into account in aging studies are simultaneously involved. The analysis of the model parameters highlights the prevalence of temperature compared to current density on the luminance performance of OLEDs. Non-linear models appear as the most accurate.

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Constant-Step-Stress Accelerated Life Test of White OLED Under Weibull Distribution Case

Cited by 26 publications

References 8 publications

Accelerated Degradation Tests Modeling Based on the Nonlinear Wiener Process with Random Effects

Accelerated Degradation Tests Modeling Based on the Nonlinear Wiener Process with Random Effects

Origin of Subthreshold Turn-On in Quantum-Dot Light-Emitting Diodes

Modeling the Luminance Degradation of OLEDs Using Design of Experiments

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