Interface Dipoles for Tuning Energy Level Alignment in Organic Thin Film Devices

Nüesch, Frank

doi:10.2533/chimia.2013.796

Cited by 9 publications

(8 citation statements)

References 171 publications

(190 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[50] A large V BI may indicate a considerable modification of the metal work functions in the presence of thin organic layers and/or the perovskite layer, or that the built-in potential is a result of remotely doped TL in our cell. [82,83] Although a built-in potential across the complete device (in the dark) is indeed necessary to achieve a well-performing device, it is an interesting question whether it is possible that the V BI drops only across the transport layers but not across the perovskite layer, as it is sometimes assumed in the literature. To investigate this, we artificially increase the dielectric constant in the perovskite layer which screens the field in the perovskite, thereby redistributing the relative potential drop across the perovskite layer and the TLs.…”

Section: Device Built-in Potential and Energy-level Alignmentmentioning

confidence: 99%

Pathways toward 30% Efficient Single‐Junction Perovskite Solar Cells and the Role of Mobile Ions

et al. 2021

View full text Add to dashboard Cite

Perovskite semiconductors have demonstrated outstanding external luminescence quantum yields, enabling high power conversion efficiencies (PCEs). However, the precise conditions to advance to an efficiency regime above monocrystalline silicon cells are not well understood. Herein, a simulation model that describes efficient p–i–n‐type perovskite solar cells well and a range of different experiments is established. Then, important device and material parameters are studied and it is found that an efficiency regime of 30% can be unlocked by optimizing the built‐in voltage across the perovskite layer using either highly doped (1019 cm−3) transport layers (TLs), doped interlayers or ultrathin self‐assembled monolayers. Importantly, only parameters that have been reported in recent literature are considered, that is, a bulk lifetime of 10 μs, interfacial recombination velocities of 10 cm s−1, a perovskite bandgap ( E gap ) of 1.5 eV, and an external quantum efficiency (EQE) of 95%. A maximum efficiency of 31% is predicted for a bandgap of 1.4 eV. Finally, it is demonstrated that the relatively high mobile ion density does not represent a significant barrier to reach this efficiency regime. The results of this study suggest continuous PCE improvements until perovskites may become the most efficient single‐junction solar cell technology in the near future.

show abstract

Section: Device Built-in Potential and Energy-level Alignmentmentioning

confidence: 99%

Pathways toward 30% Efficient Single‐Junction Perovskite Solar Cells and the Role of Mobile Ions

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The reader could also read an excellent comprehensive overview on dipole effects at the interfaces reported by Nüesch. [287] In 2015, Würfel's group did a pioneering work through numerical simulation of different solar cells architectures. [288] They explained that the essential requirement for efficient charge separation and further collection at the electrode is to create layers featuring highly dominant hole and electron conductivities near the anode and cathode, respectively.…”

Section: Charge Transporting Layermentioning

confidence: 99%

Merging Biology and Photovoltaics: How Nature Helps Sun‐Catching

Cavinato

Fresta

Ferrara

et al. 2021

Advanced Energy Materials

View full text Add to dashboard Cite

conditions. This makes difficult to further reduce the cost of electricity production. [7,8] Furthermore, although solar energy is a renewable source, it does not mean that any kind of photovoltaics (PV) is sustainable. For instance, silicon is an essential material in electronics and solar industries and, up to date, is irreplaceable. Despite its abundancy in Earth's crust, it is for the vast majority (80%) present as ferrosilicon, whose purification is expensive and highly pollutant. The production of 1 ton of silicon requires 6 tons of raw materials, almost 3 tons of Quartz, 1.5 tons of reducing agents, 1.5 tons of wood and 13 000 kWh of energy. [9,10] Therefore, in 2014 the EU commission included silicon metal in the critical raw material (CRM) list. [11] In this context, the third generation PV has reborn, offering cost-effective and efficient CRM-free devices with a lower reliance on the incident angle of light and integration in smart-end applications, like flexible and wearable devices, [12][13][14] fully transparent solar cells and windows, [15,16] and biocompatible devices. [17][18][19] The leading third generation SCs are organic solar cells (OSCs), [20][21][22] perovskite solar cells (PSCs), [23][24][25][26][27] and dye-sensitized solar cells (DSSCs). [28][29][30] Despite their versatile applications and high performances, sustainability still represents a major issue toward becoming an ideal energy technology in the mid-long term future. Among others, fullerene-based materials are toxic, [31] indium tin oxide (ITO) is brittle, chemically unstable, and expensive due to limited indium sources on Earth's crust. [32,33] Cobalt is also listed as CRM, [11] while cadmium, selenium, lead and ruthenium are toxic materials. [34,35] With regard to flexible devices, polyethylene terephthalate (PET) is the standard substrate; though its environmental footprint is critical and its nonbiodegradable properties lead to harmful effects in living organisms. [36] This has fueled a strong cooperation among the fields of engineering, biology, chemistry, and physics to discover new strategies for cost-effectiveness preparation and implementation of bio-derived materials in highly performing PVs.In general, this cooperation constitutes a part of the emerging and multidisciplinary field of biophotonics, [37] which involves biomedical optics, [38] living light, [39][40][41] biomimetic, biomaterials and bioengineered compounds, as well as fabrication/implementation methods applied to optoelectronics [42] and photonics, [43] among others. For instance, artificial lightning and biology have been recently merged with the implementation of cellulose, chitosan, silk, and fluorescent proteins as Accomplishing sustainability in optoelectronics, in general, and photovoltaics (PV), in particular, represents a crucial milestone in green photonics. Third generation PV technologies, such as organic solar cells (OSCs), perovskite solar cells (PSCs), and dye-sensitized solar cells (DSSCs) have reached a mature age and are slowly making thei...

show abstract

“…One such strategy is replacing the "conventional" architecture with an "inverted" one which allows the use of a high work moment leads to a shift in the electrode's Fermi level [34,35] and results in a more efficient carrier-selective contact. [36] In addition, based on the "like-dissolves-like" rule-of-thumb, it also makes EELs highly soluble in polar green solvents such as water and alcohol. [37] In a review on interfacial dipoles utilized in organic and perovskite solar cells, Chen et al concluded that using these materials as interlayers at contacts can help realize high efficiency, nontoxicity, and thickness-insensitivity features for large-scale commercialization.…”

Section: Introductionmentioning

confidence: 99%

The Use of Green‐Solvent Processable Molecules with Large Dipole Moments in the Electron Extraction Layer of Inverted Organic Solar Cells as a Universal Route for Enhancing Stability

Sadeghianlemraski

Nouri

Wong

et al. 2021

Advanced Sustainable Systems

View full text Add to dashboard Cite

Employing a large dipole interlayer has recently been one of the most captivating interfacial engineering approaches in organic solar cells (OSCs). In this work, the effect of using green‐solvent processable molecules with large dipole moments as electron extraction layers (DM‐EELs) on OSCs’ stability is investigated. The inverted OSCs are based on two donor–acceptor systems, with histidine and sarcosine as representative DM‐EELs and with ZnO as a control EEL. Stability results illustrate that while the dominant degradation mechanism depends on the donor–acceptor system (photoinduced degradation vs temporal degradation), using DM‐EELs substantially suppresses degradation and enhances stability in both cases. The voltage‐dependent ideality factor characteristics show that the DM‐EEL OSCs exhibit minimal recombination mechanism changes even after UV exposure. By contrast, ZnO cells are limited by significant shunt formation and UV‐induced surface recombination. Low‐temperature measurements verify that unlike the indium tin oxide (ITO)/ZnO contact, the ITO/DM‐EEL contact is not affected by trap states or work function variations. As a result, the ITO/DM‐EEL contact maintains its electron‐selectivity and resists UV‐induced surface recombination observed in the ZnO cells. The results show that using green‐solvent processable materials with large dipole moments as EELs can provide a universal route for enhancing the stability of inverted OSCs.

show abstract

Interface Dipoles for Tuning Energy Level Alignment in Organic Thin Film Devices

Cited by 9 publications

References 171 publications

Pathways toward 30% Efficient Single‐Junction Perovskite Solar Cells and the Role of Mobile Ions

Pathways toward 30% Efficient Single‐Junction Perovskite Solar Cells and the Role of Mobile Ions

Merging Biology and Photovoltaics: How Nature Helps Sun‐Catching

The Use of Green‐Solvent Processable Molecules with Large Dipole Moments in the Electron Extraction Layer of Inverted Organic Solar Cells as a Universal Route for Enhancing Stability

Contact Info

Product

Resources

About