Toward high efficiency of inverted organic solar cells: Concurrent improvement in optical and electrical properties of electron transport layers

Tsai, Shin-Hung; Ho, S. T.; Jhuo, Hung Jun; Ho, Cherng-Rong; Chen, S. A.; He, Jr‐Hau

doi:10.1063/1.4812981

Cited by 21 publications

(20 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…163,193 47,163,193 For the inverted PSCs with AZO CBLs, it is worth noting that the device performances are strongly affected by the crystallinity and stoichiometry of AZO. 193,204 This is because the electronic properties of AZO CBLs, such as work function, conductivity, mobility as well as surface states, are massively Please do not adjust margins Please do not adjust margins determined by the stoichiometry of AZO. 154,164 Tsai and coworkers have investigated the effects of Al content (from 0 to 12 mol.…”

Section: Doping Of Zno Cbls In Inverted Polymer Solar Cellsmentioning

confidence: 99%

“…It is believed that the tunable band-gap combine with the increased carrier concentration and conductivity of AZO films via Al doping, and enhanced optical absorption of P3HT are the reasons of enhanced device performance. 204 Doping ZnO with the group-III elements such as boron (B), gallium (Ga), or indium (In) for doping ZnO CBLs, is another effective way to improve the performance of inverted PSCs. 155,194,195,201 Kyaw et al investigated the correlation between the device performance and the indium contents of the sol-gel derived indium-doped ZnO (IZO) CBL in inverted PSCs.…”

Section: Doping Of Zno Cbls In Inverted Polymer Solar Cellsmentioning

confidence: 99%

See 1 more Smart Citation

ZnO cathode buffer layers for inverted polymer solar cells

Liang

Zhang

Jiang

et al. 2015

Energy Environ. Sci.

297

218

View full text Add to dashboard Cite

This article provides an overview on the design, fabrication and characterization of the most widely used cathode buffer layers (CBLs) constructed with pristine zinc oxide (ZnO), doped-ZnO, and ZnO-based composites as well as the surface modified ZnO-based CBLs for the improvement of power conversion efficiency (PCE) and long-term device stability of inverted polymer solar cells (PSCs). To achieve high PCE in inverted PSCs, the selection of an appropriate material to form the high quality CBL so as to optimize the electron collection and transport is particularly important. Among the different materials for CBL in inverted PSCs, ZnO has attracted most extensive research in view of its relatively high electron mobility, optical transparency, ease synthesis with versatile morphologies via low cost solution methods at low temperatures, and being environmentally stable. The research has revealed that the electronic processes at the interface between ZnO CBL and polymer active layer play an important role in determining the solar cells performance, and such processes are related to the ZnO CBL in terms of its morphology, microstructure, doping and surface modification. This review attempts to give a general review to better understand the impacts of (1) morphology, (2) thickness, (3) nanostructures, (4) doping, (5) surface modification and (6) composition/hybrids of ZnO CBLs on the solar cells performance. The fundamental understanding of the rapid progress of interfacial engineering made in PSCs would also be beneficial to the development of perovskite solar cells due to similar energy level and device structures.Fig. 12 (a) Schematic illustration of device structure with ZnMgO CBL. (b) Energy levels of the components in the inverted PSCs with various ZMO CBLs. (c) Optical absorption spectra of ZMO films. The inset shows an increase in the bandgap of ZMO films with the increasing of Mg content (x). (d) J-V curve of the device with the ZMO ( x = 0.3) CBL. 48 Fig. 13 (a) Chemical structures of PTB7-Th, PC 71 BM and BisNPC60-OH, (b) Schematic illustration of the proposed cathode interlayer from XPS depth profile; (c) Energy levels diagram for ZnO, InZnO, ZnO-BisC60 and InZnO-BisC60 determined from ultraviolet photoelectron spectroscopy (UPS) and UV-Vis results and for all the components in the inverted PSCs.

show abstract

Section: Doping Of Zno Cbls In Inverted Polymer Solar Cellsmentioning

confidence: 99%

Section: Doping Of Zno Cbls In Inverted Polymer Solar Cellsmentioning

confidence: 99%

ZnO cathode buffer layers for inverted polymer solar cells

Liang

Zhang

Jiang

et al. 2015

Energy Environ. Sci.

297

218

View full text Add to dashboard Cite

show abstract

“…[32][33][34][35] In parallel, Stubhan et al have demonstrated solution-processed AZO thin fi lms achieved via sol-gel techniques as ETL in P3HT:PC 60 BMbased solar cells, overcoming the inherent thickness-and interface-related issues of intrinsic ZnO. By systematically varying the Al content from 2%-12%, Tsai et al [ 41 ] have shown peak effi ciencies of 3.78% in P3HT:PC 60 BM devices (optimum Al content: 9 mol%) with Al-doped ZnO ETLs processed at 150 °C. AZO thin fi lms functioning as ETL in OPV fl exible modules (P3HT:PC 60 BM; PCE ≈3.1%), [ 38 ] in OPV tandems (PCE ≈4.5%) [ 39 ] and in terms of life time/degradation [ 40 ] has been reported before.…”

mentioning

confidence: 99%

Polymer Solar Cells with Efficiency >10% Enabled via a Facile Solution‐Processed Al‐Doped ZnO Electron Transporting Layer

Jagadamma

Al-Senani

Labban

et al. 2015

Advanced Energy Materials

149

122

View full text Add to dashboard Cite

The present work details a facile and low-temperature (125C) solution-processed Al-doped ZnO (AZO) buffer layer functioning very effectively as electron accepting/hole blocking layer for a wide range of polymer:fullerene bulk heterojunction systems, and yielding power conversion efficiency in excess of 10% (8%) on glass (plastic) substrates. We show that ammonia addition to the aqueous AZO nanoparticle solution is a critically important step toward producing compact and smooth thin films which partially retain the aluminum doping and crystalline order of the starting AZO nanocrystals. The ammonia treatment appears to reduce the native defects via nitrogen incorporation, making the AZO film a very good electron transporter and energetically matched with the fullerene acceptor. Importantly, highly efficient solar cells are achieved without the need for additional surface chemical passivation or modification, which has become an increasingly common route to improving the performance of evaporated or solution-processed ZnO ETLs in solar cells.

show abstract

“…By changing the doping concentration of Al, the energy levels in the conduction band of ZnO NPs can be tuned to better match the LUMO levels of different electron acceptor materials. Therefore, the energy level alignment between ETL and electron accepting fullerenes, as well as the built-in potential of the heterojunction, can be further improved 11 – 13 , 33 , 34 . However, high transparency in the long wavelength is depressed due to metal doped in ZnO.…”

Section: Introductionmentioning

confidence: 99%

Multiple electron transporting layers and their excellent properties based on organic solar cell

Yang

Zhang

et al. 2017

Sci Rep

View full text Add to dashboard Cite

To improve the performance of inverted polymer solar cells based on a ternary blend of polymerthieno [3,4-b] thiophene/benzodithiophene (PTB7), [6,6]-phenyl C71-butyric acid methyl ester (PC71BM) and indene-C60-bisadduct (ICBA), a two-layer structure of zinc oxide (ZnO) and Al-doped zinc oxide (AZO) nanoperticles is used to improve electron extraction. Comparing to ZnO, AZO has lower work function and thus provides larger built-in potential across the organic heterojunction, resulting in more efficient photo-current extraction and larger open circuit voltages. Optimum devices with ZnO/AZO nanoparticles show enhancement of both short circuit current and open circuit voltage, leading to a power conversion efficiency (PCE) of 8.85%. The argument of energy level buffering and surface morphology is discussed in the paper. Finally, using a trilayer electron transporting unit of ZnO/AZO/PFN, the interface dipole between the organic active layer and AZO is introduced. The PCE is further enhanced to 9.17%.

show abstract

Toward high efficiency of inverted organic solar cells: Concurrent improvement in optical and electrical properties of electron transport layers

Cited by 21 publications

References 34 publications

ZnO cathode buffer layers for inverted polymer solar cells

ZnO cathode buffer layers for inverted polymer solar cells

Polymer Solar Cells with Efficiency >10% Enabled via a Facile Solution‐Processed Al‐Doped ZnO Electron Transporting Layer

Multiple electron transporting layers and their excellent properties based on organic solar cell

Contact Info

Product

Resources

About