Impact of environmentally friendly processing on polymer solar cells: Performance, thermal stability and morphological study by imaging techniques

Bolognesi, Margherita; Prosa, Mario; Tessarolo, Marta; Donati, Giovanni; Toffanin, Stefano; Muccini, Michele; Seri, Mirko

doi:10.1016/j.solmat.2016.06.044

Cited by 25 publications

(24 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…9,[20][21][22] Recently, there has been significant interest in fabrication of OPV devices using large-area compatible coating methods such as spray coating 4,5,[23][24][25] , slot-coating, 22,26 , and blade coating. [27][28][29][30][31][32][33] Blade coating in particular is attractive for rapid exploration because a blade coater is small enough to fit onto a typical fume hood research bench, is compatible with roll-to-roll coating, and makes efficient use of expensive polymer samples. Blade coating has been used to fabricate OPV devices with over 6% efficiency 29,32 and optimized using solvent mixtures for various polymers.…”

Section: Introductionmentioning

confidence: 99%

“…Blade coating has been used to fabricate OPV devices with over 6% efficiency 29,32 and optimized using solvent mixtures for various polymers. [27][28][29][30][31][32] The optimization of solvent mixtures is used to improve the device efficiency and mutual solubility of polymer and fullerene. 32 The optimization of the self-assembly process translates to optimizing the morphology of the donor/acceptor phases.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nanoscale Morphology of Doctor Bladed versus Spin‐Coated Organic Photovoltaic Films

Pokuri

Sit

Wodo

et al. 2017

Advanced Energy Materials

View full text Add to dashboard Cite

Recent advances in the efficiency of organic photovoltaics (OPVs) have been driven by judicious selection of processing conditions that result in a 'desired' morphology. An important theme of morphology research is the need to quantify the effect of processing conditions on nanoscale morphology and to relate this information to device efficiency in a closed loop. However, accurate and comprehensive morphology quantification still remains a pressing challenge. State-of-the-art quantification methods like XRD, GIWAXS, GISAXS and TEM provide film averaged or 2D projected features that only indirectly correlate with performance, thus making causal reasoning nontrivial. Accessing the 3D distribution of material however provides a natural means of directly mapping processing conditions to device performance. In this paper, we integrate two recently developed techniquesreconstruction of 3D spatial maps of morphology (HAADF-STEM and DART) and conversion of the resulting 3D maps into intuitive morphology descriptors (GraSPI)to comprehensively image and quantify 3D morphology under various processing conditions. We apply these techniques on films generated by two of the most common fabrication techniques, doctor blading and spin coating, additionally investigating the impact of thermal annealing on these samples. We find that the morphology of all samples exhibit very high connectivity to the electrodes. Not surprisingly, thermal annealing consistently increases the average domain size of polymer/fullerene rich phases in the samples, aiding improved exciton generation. Furthermore, annealing also improves the balance of interfaces, aiding enhanced exciton dissociation. The spinannealed sample was observed to have a very balanced distribution of charge transport paths to both electrodes, aiding enhanced charge transport and collection. A comparison of morphology descriptors impacting each stage of the photo physics (exciton generation, exciton dissociation, charge transport) reveals that the spin-annealed sample exhibits superior morphology-based performance indicators. This suggests that there is substantial room for improvement of blade based methods in terms of process optimization for morphology tuning to achieve enhanced performance of large area devices.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nanoscale Morphology of Doctor Bladed versus Spin‐Coated Organic Photovoltaic Films

Pokuri

Sit

Wodo

et al. 2017

Advanced Energy Materials

View full text Add to dashboard Cite

show abstract

“…Despite DIO is a halogenated molecule, the relatively low required amount is known to have negligible environmental impact. Nevertheless, in view of large‐scale productions, it has been demonstrated that DIO can be effectively replaced with halogen‐free alternatives able to provide identical benefits . As already mentioned, o ‐DCB and TMB films processed with 2.5% (v/v) of DIO are simply named as o ‐DCB and TMB, respectively.…”

Section: Resultsmentioning

confidence: 99%

Impact of environmentally friendly processing solvents on the properties of blade‐coated polymer solar cells

Bouzid

Prosa

Bolognesi

et al. 2018

J. Polym. Sci. Part A: Polym. Chem.

Self Cite

View full text Add to dashboard Cite

High-performance polymer solar cells (PSCs) are typically fabricated by spin coating in inert atmosphere from toxic halogenated solvents such as 1,2-dichlorobenzene (o-DCB) and chlorobenzene. This fabrication process is potentially hazardous for both the humans and the environment and dramatically impacts the possibility for the organic photovoltaic technology to be adopted at large scale. In this work, efficient PSCs blade coated in air using nonhalogenated 1,2,4-trimethylbenzene (TMB) as processing solvent are demonstrated. The active layer, based on a previously synthesized benchmark polymer PFQ2Tbenzodithiophene blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM), showed an enhanced solid-state aggregation induced by the use of TMB. Compared to o-DCBprocessed devices, the solar cells fabricated from TMB resulted 10% more efficient with a power conversion efficiency of 4.20%.Interestingly, the improved photovoltaic performance resulted from the combination of synergic effects promoted by a more favorable film morphology, such as high exciton dissociation efficiency and lower bimolecular recombinations resulting in higher charge collection efficiency at the electrodes. The positive effect of TMB, compared to that of commonly employed halogenated solvents, confirms the great potential of this approach for the development of efficient PSCs for practical applications with reduced environmental impact.

show abstract

“…Two different donor materials were used for the tandem device: a high band gap polymer, HBG1 (provided by Merck), for the bottom cell, and a low band gap polymer, PMDPP3T, for the top layer. The absorption spectra of the resulting polymer:fullerene blends are reported in Figure a.…”

Section: Resultsmentioning

confidence: 99%

Efficient and Versatile Interconnection Layer by Solvent Treatment of PEDOT:PSS Interlayer for Air‐Processed Organic Tandem Solar Cells

Prosa

Tessarolo

Bolognesi³

et al. 2016

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

A robust and efficient interconnection layer (ICL) based on low conductive poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) and ZnO nanoparticles is implemented in a solution‐air‐processed, blade coated inverted polymer tandem solar cell. The commercial PEDOT:PSS (Heraeus Clevios P VP Al 4083) is modified with a fluorosurfactant to allow its deposition onto any hydrophobic active layer surface. However, this method alters the electrical and energetic properties of the PEDOT:PSS thus affecting the interface with the ZnO layer, responsible for an inefficient ICL and poorly performing tandem devices. The ohmic contact at the PEDOT:PSS/ZnO interface is successfully optimized through a simple solvent treatment of the PEDOT:PSS film surface, leading to tandem devices with power conversion efficiencies (PCEs) improved by more than 50% compared to the untreated reference system. The reported method is an easy and versatile approach to optimize the functionality of the PEDOT:PSS/ZnO ICL of inverted multijunction devices, applicable onto any organic active layer and compatible with a roll‐to‐roll production line.

show abstract

Impact of environmentally friendly processing on polymer solar cells: Performance, thermal stability and morphological study by imaging techniques

Cited by 25 publications

References 45 publications

Nanoscale Morphology of Doctor Bladed versus Spin‐Coated Organic Photovoltaic Films

Nanoscale Morphology of Doctor Bladed versus Spin‐Coated Organic Photovoltaic Films

Impact of environmentally friendly processing solvents on the properties of blade‐coated polymer solar cells

Efficient and Versatile Interconnection Layer by Solvent Treatment of PEDOT:PSS Interlayer for Air‐Processed Organic Tandem Solar Cells

Contact Info

Product

Resources

About