Ternary Solar Cells Based on Two Small Molecule Donors with Same Conjugated Backbone: The Role of Good Miscibility and Hole Relay Process

Xiao, Liangang; Liang, Tianxiang; Gao, Ke; Lai, Tianqi; Chen, Xuebin; Liu, Feng; Russell, Thomas P.; Huang, Fei; Peng, Xiaobin; Cao, Yong

doi:10.1021/acsami.7b07960

Cited by 45 publications

(30 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[73,79,80] The PBDB-T:IEICO-4F:3TT-FIC-based ternary PSCs exhibited high J ph and low J sat values, which account for the efficient photocurrent response and the sharply saturated state. [81,82] The slight reduction in the G max value of PBDB-T:IEICO-4F:3TT-FIC-based ternary PSCs is consistent with the blueshift of the absorption peaks of PBDB-T:IEICO-4F:3TT-FIC ternary films compared with PBDB-T:IEICO-4F binary films. In addition, the highest η diss and η coll values of PBDB-T:IEICO-4F:3TT-FIC-based ternary PSCs indicates efficient exciton dissociation at the PBDB-T/blend acceptor triple interface and charge carrier transport and collection between the photoactive layer and the electrode.…”

Section: Wwwadvopticalmatdesupporting

confidence: 66%

Small Energy Loss and Broad Energy Levels Offsets Lead to Efficient Ternary Polymer Solar Cells from a Blend of Two Fullerene‐Free Small Molecules as Electron Acceptors

Wang

2019

Advanced Optical Materials

View full text Add to dashboard Cite

the new polymer PE2 and PE63 as donor and with Y6 as acceptor, and achieved the better photovoltaic performance. [6,7] PSCs have several advantages, such as their light absorption tunability, mechanical flexibility, roll-to-roll manufacturing capability and so on. However, the PCE of PSCs is still inferior to their inorganic counterparts. One of the most significant factors that hinders their photovoltaic performance is the relatively large energy loss (E loss ) in the open-circuit condition with respect to the energy level offsets between the donor and acceptor, which leads to the low open-circuit voltage (V OC ) value. [8,9] In addition, there are several disadvantages involving exciton dissociation and charge carrier recombination within the photoactive layer which might function to enhance the photovoltaic performance. In parallel, the narrow spectral absorption of fullerene acceptors (e.g., [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM) and [6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM)) falling in the short-wavelengths region (from 300 to 450 nm) inherently limits the photonic absorption since most of the photon flux occurs in the visible range of the solar spectrum (longer than 450 nm). At the same time, the fullerene derivatives have the disadvantage of having a deep lowest unoccupied molecular orbital (LUMO) energy level, which limits the energy level offset between the donor and acceptor and leads to small open-circuit voltages (V OC ). [10,11] Fullerene-free electron acceptors that enable adjustable energy levels and broad visible light absorption spectra have been developed and synthesized. For instance, the absorption peak of the fullerene-free acceptor 2,2′-((2Z,2′Z)- (((4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-sindaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(4-((2-ethylhexyl)oxy)thiophene-5,2-diyl)) bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IEICO-4F) is located in the near-infrared region (the absorption peak is at 835 nm), and it has a shallow LUMO energy level (the LUMO energy level is at −4.13 eV) relative to those of PC 71 BM. [12] The new fullerenefree molecule, thieno[3,2-b]thiophene-2-(5,6-difluoro-3-oxo-2-2,3-dihydro-1H-ioden-1-ylidene)malononitrile (3TT-FIC) has a longer wavelength absorption window (the absorption peak is located at 810 nm) and a shallower LUMO energy level (the LUMO energy level is at −4.02 eV). [13] Recently, ternary strategies that use either a blend of one donor and two acceptor materials or two donor and one Ternary polymer solar cells (PSCs) are fabricated that consisted of a blend of IEICO-4F and 3TT-FIC as electron acceptors and PBDB-T as an electron donor. The power conversion efficiency (PCE) of ternary PSCs is increased from 9.9% to 11.22% via the blend of IEICO-4F and 3TT-FIC as electron acceptors (the ratio of IEICO-4F:3TT-FIC is 6:4), which enhances the opencircuit voltage (V OC ) from 0.71 to 0.78 V. The main contribution of the blended acceptor is its broad energy level offset between ...

show abstract

Section: Wwwadvopticalmatdesupporting

confidence: 66%

Small Energy Loss and Broad Energy Levels Offsets Lead to Efficient Ternary Polymer Solar Cells from a Blend of Two Fullerene‐Free Small Molecules as Electron Acceptors

Wang

2019

Advanced Optical Materials

View full text Add to dashboard Cite

show abstract

“…Moreover, the newly designed small molecule does not display an obvious vibronic shoulder peak unlike the other two donors, suggesting weak intermolecular interactions between the conjugated backbones or decreased degree of molecular aggregation. [24,37] Adv. The HOMO/LUMO levels were calculated from the onset oxidation and reduction potential ( Figure S2, Supporting Information) as −5.33 eV and −3.50 eV, respectively, which indicate a significant reduction when compared with energy levels of DCAO3TBDTT and DR3T-BDTT.…”

Section: Design Synthesis Optical and Electrochemical Propertiesmentioning

confidence: 99%

“…Actually, incorporating a structurally similar donor to the binary system is also considered as an effective way to enhance the photovoltaic performance . Previously, Peng and co‐workers have reported that the synergistic effects of the two structurally similar donors including good miscibility and hole relay process have played a critical part in facilitating the charge transportation for the ternary system . Recently, we have also reported a type of all‐small‐molecule ternary solar cell consisting of two compatible small molecules as donors and PC 71 BM as the acceptor .…”

Section: Introductionmentioning

confidence: 99%

Constructing High‐Performance All‐Small‐Molecule Ternary Solar Cells with the Same Third Component but Different Mechanisms for Fullerene and Non‐fullerene Systems

Chang

Zhu

et al. 2019

Advanced Energy Materials

View full text Add to dashboard Cite

donors used, OSCs fall into two categories: polymer solar cells and small-molecule solar cells. While according to the acceptor used, they can be divided into fullerene solar cells and non-fullerene solar cells. Polymer solar cells have always been the focus of attention, and a breakthrough, that is., a power conversion efficiency (PCE) of over 15% has been achieved for this type of device. [9] In contrast, a noticeable gap exists between small-molecule solar cells and polymer solar cells whether in terms of performances or the research scale. However, small molecule donors still have some unique advantages over polymer donors, such as definite chemical structure, extremely high purity and excellent reproducibility, which could be better suited for future large-scale applications of OSCs. [10][11][12][13] Particularly, there has been a new upsurge for developing all-small-molecule solar cells owing to the widespread use of non-fullerene acceptors. [14,15] Although currently both fullerene-and non-fullerene-based allsmall-molecule solar cells present high PCEs of over 11%, [16,17] the defects in each system should be clearly addressed. For instance, due to the weak absorption ability of fullerene acceptors, such as [6,6]-phenyl-C 61 -butyric acid methyl ester (PC 61 BM) and [6,6]-phenyl-C 71 -butyric acid methyl ester (PC 71 BM), in the short-wavelength and near-infrared regions, it is difficult to obtain much higher photocurrent. [18] On the other hand, when selecting a non-fullerene acceptor, like IDIC, [19] which possesses superior crystallization capability, [20] it is hard to achieve ideal film morphology with nanoscale phase separation. Therefore, overcoming these issues for binary devices is of great importance for continued evolution of all-small-molecule solar cells.Here, utilizing the individual advantages of both fullerene and non-fullerene acceptors has been demonstrated as an attractive strategy to resolve the above-mentioned problems. [21] Recently, several cases of all-small-molecule ternary solar cells with significant increase in the PCE, which employed one small molecule donor material, one fullerene acceptor (PC 71 BM) and one non-fullerene acceptor, have been reported. [21,22] In these cases, PC 71 BM has played an important role in modulating the film morphology of the ternary system, which could significantly facilitate charge generation and transportation and suppress charge recombination. As a result, the short-circuit current Two types of all-small-molecule ternary solar cells consisting of two smallmolecule donors and one acceptor (fullerene/non-fullerene) are developed. Interestingly, both these devices have a common component: a carefully designed medium bandgap small molecule, which possesses appropriate energy levels and displays good compatibility with the host donor. In the fullerene system, the charge-relaying role of the additive donor is confirmed by the improved charge transportation and suppressed charge recombination. While in the non-fullerene system, the mixed face-on and ed...

show abstract

“…[26][27][28] And the expanded and enhanced absorptions in J-aggregation-based films provide the potential chance to fabricate broader light response and larger short-circuit current (J SC ) solar cell devices. Some of porphyrin derivatives are near-infrared (NIR) organic semiconductors with optical bandgap less than 1.5 eV which have attracted much attention due to their great contribution to the field of NIR photodetector, 29,30 SM-OSCs, [31][32][33][34][35][36][37][38][39][40][41] ternary solar cells [42][43][44][45][46] and tandem solar cells. 47,48 In this contribution, we report dimer porphyrin molecule ZnP2-DPP 49 (Figure 1 .…”

Section: Introductionmentioning

confidence: 99%

Improving the efficiencies of small molecule solar cells by solvent vapor annealing to enhance J-aggregation

Xiao

et al. 2019

J. Mater. Chem. C

Self Cite

View full text Add to dashboard Cite

show abstract

Ternary Solar Cells Based on Two Small Molecule Donors with Same Conjugated Backbone: The Role of Good Miscibility and Hole Relay Process

Cited by 45 publications

References 54 publications

Small Energy Loss and Broad Energy Levels Offsets Lead to Efficient Ternary Polymer Solar Cells from a Blend of Two Fullerene‐Free Small Molecules as Electron Acceptors

Small Energy Loss and Broad Energy Levels Offsets Lead to Efficient Ternary Polymer Solar Cells from a Blend of Two Fullerene‐Free Small Molecules as Electron Acceptors

Constructing High‐Performance All‐Small‐Molecule Ternary Solar Cells with the Same Third Component but Different Mechanisms for Fullerene and Non‐fullerene Systems

Improving the efficiencies of small molecule solar cells by solvent vapor annealing to enhance J-aggregation

Contact Info

Product

Resources

About