Dark carrier recombination in organic solar cell

Wang, Ying Xuan; Tseng, Shin Rong; Meng, Hsin‐Fei; Lee, Kuan Chen; Liu, Chiou Hua; Horng, Sheng Fu

doi:10.1063/1.2972115

Cited by 26 publications

(21 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 In contrast, for planar heterojunction (PHJ) cells recent models claim that V oc is almost independent of the electrode work functions. 12,13 This result was also supported by experimental findings. 12,14,15 The models attribute the weak work function dependence of V oc to band bending which partly compensates the change of the internal field.…”

Section: Introductionsupporting

confidence: 79%

Influence of the indium tin oxide/organic interface on open-circuit voltage, recombination, and cell degradation in organic small-molecule solar cells

et al. 2011

View full text Add to dashboard Cite

In this paper we investigate the performance and stability of small-molecule organic solar cells with respect to the indium tin oxide (ITO)/organic interface. Different zinc-phthalocyanine (ZnPc)/fullerene (C 60 ) cell architectures with and without ITO O 2 -plasma treatment are compared and tested with respect to their degradation behavior under illumination in inert atmosphere. Photoelectron spectroscopy (UPS and XPS) shows that the O 2 -plasma treatment increases the ITO work function from 4.3 eV up to 5.6 eV. We find that both the increased ITO work function as well as the introduction of an electron blocking layer between ITO and the mixed donor/acceptor layer increases the open-circuit voltage V oc by more than 200 mV. For both cases our continuum approach device simulation quantitatively relates the increase of V oc to a reduced contact recombination and thus a reduced dark current. For cells built on ozone treated ITO we find a fast cell degradation caused by the UV part of the AM 1.5 spectrum. We identify the degradation, which manifests itself in a decrease of V oc of up to 25%, as a partial reversion of the plasma induced ITO work function increase. Additionally, we demonstrate that the degradation can be reduced by structural changes in the cell architecture, leading to improved cell stability. We present a comprehensive study of the recombination at the ITO/organic interface and its influence on the open-circuit voltage and the cell stability.

show abstract

Section: Introductionsupporting

confidence: 79%

Influence of the indium tin oxide/organic interface on open-circuit voltage, recombination, and cell degradation in organic small-molecule solar cells

et al. 2011

View full text Add to dashboard Cite

show abstract

“…There are also several studies which addressed different reasons (considering different aspects) for the fact that higher mobilities may be unfavorable for device performance as a result of Voc reduction. For instance, authors of [26,51] showed that a reduction of Voc is due to recombination of dark charge carriers injected from the contacts as their density increases with the higher mobility.…”

Section: Ultimate Pce Map For Mobility-dependent (Lagevin Type) Lossesmentioning

confidence: 99%

Sensitivity of the Drift-Diffusion Approach in Estimating the Power Conversion Efficiency of Bulk Heterojunction Polymer Solar Cells

2017

View full text Add to dashboard Cite

There are numerous theoretical approaches to estimating the power conversion efficiency (PCE) of organic solar cells (OSCs), ranging from the empirical approach to calculations based on general considerations of thermodynamics. Depending on the level of abstraction and model assumptions, the accuracy of PCE estimation and complexity of the calculation can change dramatically. In particular, PCE estimation with a drift-diffusion approach (widely investigated in the literature), strongly depends on the assumptions made for the physical models and optoelectrical properties of semiconducting materials. This has led to a huge deviation as well as complications in the analysis of simulated results aiming to understand the factors limiting the performance of OSCs. In this work, we intend to highlight the complex relation between mobility, exciton dynamics, nanoscale dimension, and loss mechanisms in one framework. Our systematic analysis represents key information on the sensitivity of the drift-diffusion approach, to estimate how physical parameters and physical processes bind the PCE of the device under the influence of structure, contact, and material layer properties. The obtained results ultimately led to recommendations for putting effort into certain properties to get the most out of avoidable losses, presented the impact and importance of modification of material properties, and in particular, recommended to what degree the design of new material could improve OSC performance.

show abstract

“…[3][4][5][6][7] It has been shown that there is an optimum value of the mobility that leads to a peak efficiency. [3][4][5][6] Mobilities lower than the optimum value lead to lower efficiencies due to significant reductions in the dissociation rate of polaron pairs into free charge carriers, 3 together with less efficient charge extractions.…”

Section: Introductionmentioning

confidence: 99%

Combined influence of carrier mobility and dielectric constant on the performance of organic bulk heterojunction solar cells

et al. 2014

View full text Add to dashboard Cite

It has been shown that there is an optimum charge carrier mobility that leads to a peak in the efficiency for organic bulk heterojunction solar cells with mobility-dependent recombination rate. Hence, improving the mobility is considered as one of the ways to increase the efficiency. In this study, we investigate the combined influence of charge carrier mobility and dielectric constant on the performance of organic bulk heterojunction solar cells by performing drift-diffusion calculations. We find that a higher dielectric constant leads to a higher peak efficiency together with a lower optimum mobility. We also find that if the dielectric constant of the active material can be increased significantly (to around 8 or higher), it is then possible that the mobility of the active material need not to be improved in order to achieve the maximum efficiency. This study demonstrates the importance of knowing the interplay between the mobility and the dielectric constant with regard to the efficiency.

show abstract

Dark carrier recombination in organic solar cell

Cited by 26 publications

References 16 publications

Influence of the indium tin oxide/organic interface on open-circuit voltage, recombination, and cell degradation in organic small-molecule solar cells

Influence of the indium tin oxide/organic interface on open-circuit voltage, recombination, and cell degradation in organic small-molecule solar cells

Sensitivity of the Drift-Diffusion Approach in Estimating the Power Conversion Efficiency of Bulk Heterojunction Polymer Solar Cells

Combined influence of carrier mobility and dielectric constant on the performance of organic bulk heterojunction solar cells

Contact Info

Product

Resources

About