Efficient non-fullerene organic solar cells employing sequentially deposited donor–acceptor layers

Zhang, Jiangbin; Kan, Bin; Pearson, Andrew J.; Parnell, Andrew J.; Cooper, Joshaniel F. K.; Liu, Xiaoke; Conaghan, Patrick J.; Hopper, Thomas R.; Wu, Yutian; Wan, Xiangjian; Gao, Feng; Bakulin, Artem A.; Chen, Yongsheng; Friend, Richard H.

doi:10.1039/c8ta06860g

Cited by 52 publications

(61 citation statements)

References 77 publications

(78 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both values are in good agreement with reported CT energy estimates for these material systems (1.54 and 1.53 eV, respectively), obtained by characterising the overlap of the external quantum efficiency and the electroluminescence of the blend. 8,107 As mentioned above, the errors listed for the photovoltaic gaps are of statistical nature, demonstrating that the photovoltaic gap remains highly constant with almost no deviation throughout the bulk heterojunction. While the estimated photovoltaic gaps include uncertainties due to the use of optical gaps, our method provides accurate measurements of the HOMO-HOMO offsets for all investigated material systems.…”

Section: Energetic Landscape Of P3ht:pc60bm and P3ht/pc60bm And Of Otmentioning

confidence: 78%

“…117 UPS depth profiling will allow the simultaneous determination of the doping depth evolution and its effect on the energetic landscape within the layer. Novel film structures, such as sequentially deposited donor-acceptor layers, 107 can be also investigated in great detail with our technique. Finally, the ability to extract compositional profiles from electronic structure measurements is in itself intriguing.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Visualizing the Vertical Energetic Landscape in Organic Photovoltaics

Lami

Weu

Zhang

et al. 2019

Joule

Self Cite

View full text Add to dashboard Cite

Energy level diagrams in organic electronic devices play a crucial role in device performance and interpretation of device physics. In the case of organic solar cells, it has become routine to estimate the photovoltaic gap of the donor:acceptor blend using the energy values measured on the individual blend components, resulting in a poor agreement with the corresponding open-circuit voltage of the device. To address this issue, we developed a method that allows a direct visualisation of the vertical energetic landscape in the blend, obtained by combining ultraviolet photoemission spectroscopy and argon cluster etching. We investigate both model and high-performance photovoltaic systems and demonstrate that the resulting photovoltaic gaps are in close agreement with the measured CT energies and open-circuit voltages. Furthermore, we show that this method allows us to study the evolution of the energetic landscape upon environmental degradation, critically important for understanding degradation mechanisms and development of mitigation strategies.

show abstract

Section: Energetic Landscape Of P3ht:pc60bm and P3ht/pc60bm And Of Otmentioning

confidence: 78%

Section: Discussionmentioning

confidence: 99%

Visualizing the Vertical Energetic Landscape in Organic Photovoltaics

Lami

Weu

Zhang

et al. 2019

Joule

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, a promising alternative method, which is known as “sequential processing,” (SqP) was developed . In this method, the donor and acceptor layers are cast sequentially using two different solutions.…”

Section: Introductionmentioning

confidence: 99%

“…Otherwise, it is entirely possible for the underlying polymer film to get destroyed wholly or partially after spin casting the acceptor on top of it. Therefore, most of the reports are based on carefully choosing an orthogonal/quasiorthogonal solvent either by using low boiling point solvent(s) (e.g., chloroform (CF), tetrahydrofuran (THF), DCM) or including a small amount of high boiling point solvent (typically used as a cosolvent) for better interdiffusion of acceptor molecules . Despite the high performance, limited choices of acceptor's solvent could seriously hinder industrial production.…”

Section: Introductionmentioning

confidence: 99%

Temperature‐Dependent Aggregation Donor Polymers Enable Highly Efficient Sequentially Processed Organic Photovoltaics Without the Need of Orthogonal Solvents

Arunagiri

Zhang

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

The conventional method to prepare bulk-heterojunction organic photovoltaics (OPVs) is a one-step method from the blend solution of donor and acceptor materials, known as blend-casting (BC). Recently, an alternative method was demonstrated to achieve high efficiencies (13%) comparable to state-of-the-art BC devices. This two-step-coating method, known as "sequential processing," (SqP) involves sequential deposition of the donor and then the acceptor from two orthogonal solvents. However, the requirement of orthogonal solvents to process the donor and acceptor constrains the choice of materials and processing solvents. In this paper, an improved version of SqP method without the need for using orthogonal solvents is reported. The success is based on donor polymers with strong temperature-dependent aggregation properties whose solution can be processed at a high temperature, but the resulting film becomes completely insoluble at room temperature, which allows for the processing of overlying acceptors from a wide range of nonorthogonal solvents. With this approach, efficient SqP OPVs is demonstrated based on a range of donor/acceptor materials and processing solvents, and, in every single case, SqP OPVs can outperform their BC counterparts. The results broaden the solvent choices and open a much larger window to optimize the processing parameters of SqP method.

show abstract

“…Promoted by the prosperous development of small molecular nonfullerene acceptors and diverse donor materials, the power conversion efficiencies (PCE) of polymer solar cells have exceeded 14%, suggesting the bright promise of PSCs in practical applications . Moreover, device optimization including interfacial and device engineering also plays a crucial role in promoting the development of PSCs . Nevertheless, restrained by the prerequisite molecular energy level differences of the donor and acceptor materials, the conventional binary PSCs built with one donor–acceptor pair can hardly harvest the solar photons as much as possible in a wide range of solar spectrum .…”

Section: Introductionmentioning

confidence: 99%

Ternary Polymer Solar Cells with High Efficiency of 14.24% by Integrating Two Well‐Complementary Nonfullerene Acceptors

Jiang

Wang

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Ternary polymer solar cells (PSCs) are one of the most promising device architectures that maintains the simplicity of single-junction devices and provides an important platform to better tailor the multiple performance parameters of PSCs. Herein, a ternary PSC system is reported employing a wide bandgap polymeric donor (PBTA-PS) and two small molecular nonfullerene acceptors (labeled as LA1 and 6TIC). LA1 and 6TIC keep not only wellmatched absorption profiles but also the rational crystallization properties. As a result, the optimal ternary PSC delivers a state of the art power conversion efficiency (PCE) of 14.24%, over 40% higher than the two binary devices, resulting from the prominently increased short-circuit current density (J sc ) of 22.33 mA cm −2 , moderate open-circuit voltage (V oc ) of 0.84 V, and a superior fill factor approaching 76%. Notably, the outstanding PCE of the ternary PSC ranks one of the best among the reported ternary solar cells. The greatly improved performance of ternary PSCs mainly derives from combining the complementary properties such as absorption and crystallinity. This work highlights the great importance of the rational design of matched acceptors toward highly efficient ternary PSCs.

show abstract

Efficient non-fullerene organic solar cells employing sequentially deposited donor–acceptor layers

Abstract: A new fabrication method via sequentially depositing donor and acceptor layers can push the power conversion efficiency of organic solar cells based on non-fullerene acceptors to over 10%.

Cited by 52 publications

References 77 publications

Visualizing the Vertical Energetic Landscape in Organic Photovoltaics

Visualizing the Vertical Energetic Landscape in Organic Photovoltaics

Temperature‐Dependent Aggregation Donor Polymers Enable Highly Efficient Sequentially Processed Organic Photovoltaics Without the Need of Orthogonal Solvents

Ternary Polymer Solar Cells with High Efficiency of 14.24% by Integrating Two Well‐Complementary Nonfullerene Acceptors

Contact Info

Product

Resources

About