Perovskite Photovoltaic Devices: Enhancing the Open‐Circuit Voltage of Perovskite Solar Cells by up to 120 mV Using π‐Extended Phosphoniumfluorene Electrolytes as Hole Blocking Layers (Adv. Energy Mater. 33/2019)

An, Qingzhi; Sun, Qing; Weu, Andreas; Becker‐Koch, David; Paulus, Fabian; Arndt, Sebastian; Stuck, Fabian; Hashmi, A. Stephen K.; Tessler, Nir; Vaynzof, Yana

doi:10.1002/aenm.201970126

Cited by 8 publications

(5 citation statements)

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“…This HOMO value matches well with that of other HTMs such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) or selfassembled molecules (SAMs) that are commonly used in optoelectronic devices. [59][60][61][62][63] A density function theory (DFT) calculation using the model of TPA-NHC-Au (0) was carried out to study the electronic coupling between the AuNP and TPA unit (Figure S15, Supporting Information). In the HOMO and LUMO orbits, the electron can be delocalized over Au atom and conjugated NHC-TPA moiety, indicating a highly conductive NHC-Au bond.…”

Section: Resultsmentioning

confidence: 99%

Gold Nanoparticles with N‐Heterocyclic Carbene/Triphenylamine Surface Ligands: Stable and Electrochromically Active Hybrid Materials for Optoelectronics

Sun,

Singh,

Zhang

et al. 2024

Advanced Science

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Organic‐hybrid particle‐based materials are increasingly important in (opto)electronics, sensing, and catalysis due to their printability and stretchability as well as their potential for unique synergistic functional effects. However, these functional properties are often limited due to poor electronic coupling between the organic shell and the nanoparticle. N‐heterocyclic carbenes (NHCs) belong to the most promising anchors to achieve electronic delocalization across the interface, as they form robust and highly conductive bonds with metals and offer a plethora of functionalization possibilities. Despite the outstanding potential of the conductive NHC‐metal bond, synthetic challenges have so far limited its application to the improvement of colloidal stabilities, disregarding the potential of the conductive anchor. Here, NHC anchors are used to modify redox‐active gold nanoparticles (AuNPs) with conjugated triphenylamines (TPA). The resulting AuNPs exhibit excellent thermal and redox stability benefiting from the robust NHC‐gold bond. As electrochromic materials, the hybrid materials show pronounced color changes from red to dark green, a highly stable cycling stability (1000 cycles), and a fast response speed (5.6 s/2.1 s). Furthermore, TPA‐NHC@AuNP exhibits an ionization potential of 5.3 eV and a distinct out‐of‐plane conductivity, making them a promising candidate for application as hole transport layers in optoelectronic devices.

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Section: Resultsmentioning

confidence: 99%

Gold Nanoparticles with N‐Heterocyclic Carbene/Triphenylamine Surface Ligands: Stable and Electrochromically Active Hybrid Materials for Optoelectronics

Sun,

Singh,

Zhang

et al. 2024

Advanced Science

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“…A thin layer of bathocuproine (BCP) is introduced between the PC 61 BM layer and the Ag contact in order to achieve efficient holeblocking. [48,49] The current density-voltage (JV ) characteristics of the resulting photovoltaic devices are shown in Fig. S1.…”

Section: Resultsmentioning

confidence: 99%

“…[94] The MAPbI 3 active layer was formed using the lead acetate trihydrate route following previous works. [44,49] In short, the perovskite solution (at different stoichiometry of 2.96:1 to 3.06:1 in 0.02 steps PbAc 2 :MAI) was spin cast at 2000 rpm for 60 s in a dry air filled glovebox (relative humidity < 0.5 %). After blowing 25 s and drying 5 min, the as-spun films were annealed at 100 • C for 5 min forming a uniform perovskite layer.…”

Section: Discussionmentioning

confidence: 99%

Probing the ionic defect landscape in halide perovskite solar cells

Reichert,

An,

Woo

et al. 2020

Preprint

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Metal halide perovskites are a remarkable class of materials with particular promise for application in optoelectronics. Like in any semiconductor, defects in perovskites play a critical role in determining their properties and performance in optoelectronic devices, however many open questions regarding the nature of ionic defects remain unanswered. In this work we apply impedance spectroscopy and deep-level transient spectroscopy to characterize the ionic defect landscape in methylammonium lead triiodide (MAPbI 3 ) perovskites in which defects were purposely introduced by fractionally changing the precursor stoichiometry. Our results indicate that variation of the ionic defect landscape has a profound influence on the electronic landscape, exemplified by its impact on the device built-in potential, and consequently, the open-circuit voltage. Moreover, we find that all measured ionic defects fulfill the Meyer-Neldel rule with a characteristic energy, which corresponds to the underlying ionic hopping process in perovskite materials. These findings allow a defect categorization of our data and literature values.

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“…Processing: The MAPbI 3 active layer was processed by the lead acetate trihydrate approach [58][59][60] using a precursor solution with a stoichiometry of 1:3.00 MAI:PbAc 2 and an additive of hypophosphoric acid at a ratio of 1.7 µl/100 mg MAI. The perovskite solution was spin cast at 2000 rpm for 60 s in a dry-air filled glovebox (relative humidity < 0.5 %) on top of a modified poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (m-PEDOT:PSS) as hole-transport layer.…”

Section: Methodsmentioning

confidence: 99%

Open-Circuit Voltage Limitation by Surface Recombination in Perovskite Solar Cells

Reichert,

Goetz,

Wöpke

et al. 2020

Preprint

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Fundamental electronic processes such as charge-carrier transport and recombination play a critical role in determining the efficiency of hybrid perovskite solar cells. The presence of mobile ions complicates the development of a clear understanding of these processes as the ions may introduce exceptional phenomena such as hysteresis or giant dielectric constants. As a result, the electronic landscape, including its interaction with mobile ions, is difficult to access both experimentally and analytically. To address this challenge, we applied a series of small perturbation techniques including impedance spectroscopy (IS), intensity-modulated photocurrent spectroscopy (IMPS) and intensity-modulated photovoltage spectroscopy (IMVS) to planar MAPbI 3 perovskite solar cells. Our measurements indicate that both electronic as well as ionic responses can be observed in all three methods and assigned by literature comparison. The results reveal that the dominant charge-carrier loss mechanism is surface recombination by limitation of the quasi-Fermi level splitting. The interaction between mobile ions and the electronic charge carriers leads to a shift of the apparent diode ideality factor from 0.74 to 1.64 for increasing illumination intensity, despite the recombination mechanism remaining unchanged.

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Perovskite Photovoltaic Devices: Enhancing the Open‐Circuit Voltage of Perovskite Solar Cells by up to 120 mV Using π‐Extended Phosphoniumfluorene Electrolytes as Hole Blocking Layers (Adv. Energy Mater. 33/2019)

Cited by 8 publications

References 0 publications

Gold Nanoparticles with N‐Heterocyclic Carbene/Triphenylamine Surface Ligands: Stable and Electrochromically Active Hybrid Materials for Optoelectronics

Gold Nanoparticles with N‐Heterocyclic Carbene/Triphenylamine Surface Ligands: Stable and Electrochromically Active Hybrid Materials for Optoelectronics

Probing the ionic defect landscape in halide perovskite solar cells

Open-Circuit Voltage Limitation by Surface Recombination in Perovskite Solar Cells

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