Efficient ternary organic solar cells with high absorption coefficient DIB-SQ as the third component

A series of organic solar cells（OSCs） are prepared with PTB7：PC71 BM as the host materials and DIB-SQ as the third component. The power conversion efficienty（PCE） of OSCs can be improved from 6.79% to 7.92% by incorporating 6 wt%DIB-SQ into donors, resulting from the enhanced short circuit current density（JSC and fill factor（FF）. The increased JSCof the optimized ternary OSCs should be attributed to the enhanced photon harvesting of teranry active layer by incorporating DIB-SQ. Meanwhile, FF of the optimized ternary OSCs should be due to the optimied phase separation. The open circuit voltage（VOC） of tenray OSCs can be maintained at a constant of 0.75 V, indicating that all photogenerated holes willl be transported along the channels formed by PTB7.

Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of PTB7:PC71BM photovoltaic system

Effects of a benzotriazole(BTA)-based small molecule,BTA2,as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]](PTB7):[6,6]-phenyl-C71-butyric acid methyl ester(PC71BM)organic solar cells(OSCs)were investigated by optical simulation of a transfer matrix model(TMM),photo-induced charge extraction by linearly increasing voltage(photo-CELIV)technique,atomic force microscope(AFM),and the Onsager–Braun model analysis.BTA2 is an A_(2)-A_(1)-D-A_(1)-A_(2)-type non-fullerene small molecule with thiazolidine-2,4-dione,BTA,and indacenodithiophene as the terminal acceptor(A_(2)),bridge acceptor(A_(1)),and central donor(D),respectively.The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum.The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2,resulting in more photogenerated excitons in the ternary OSCs.The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs.AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor,which is disadvantageous to charge carrier transport.The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs,the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.

What Will Happen, If Zero SpinParticle Possesses Spin Rotational Construction, With Non-Zero Eigenvalues Of Spin Angular Momentum?

There is no any spin rotational construction for zero spin particle, Casimir operator and the thired component of zero spin particle areandrespectively. Further, there are no spin interactions between zero spin particle and other spin particles. This paper shows: in Spin Topological Space, STS [1], the third component of zero spin particle possesses non-zero eigenvalues besides original zero value, this leads to a miraculous spin interaction phenomenon between zero spin particle and other spin particles. In STS, zero spin particle could "dissolve other spin particles", degrade the values of their Casimir operator, and decay these spin particles into other forms of spin particle.

Facile access to C-N bonds via unexpected side reactions of Knoevenagel condensation and their application in high-efficiency organic solar cells

The construction of C-N bonds is of great importance in the fields of biology,medicine,chemistry and materials science.Here,the replacement of organic base from pyridine to piperidine in the Knoevenagel condensation process unexpectedly yields a series of novel organic molecules containing C-N bonds.Interestingly,the synthesis method does not require any external transition-metals catalysis,and photo-/electro-catalysis.Additionally,when the new compound 1b is added as a third component to a well-known binary system of PM6:Y6,the efficiency of the organic solar cell is significantly improved,resulting in an outstanding efficiency of 18.0%,which is one of the highest values reported to date for PM6:Y6-based ternary organic solar cells.

A new nonfullerene acceptor with an extended π conjugation core enables ternary organic solar cells approaching 19%efficiency

In organic solar cells(OSCs),it is an effective way to improve the power conversion efficiency(PCE)by adding a guest component with appropriate absorption and energy levels in the host system.Herein,a new nonfullerene acceptor(NFA)named TBF-2Cl was developed by the strategy of expanding theπconjugated core of 2,2’-(((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b’]dithiophene-2,7-diyl)bis(methaneylylidene))bis(5,6-dichloro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile(IDT-4Cl)with two benzene rings.With increase of benzene units,TBF-2Cl exhibits higher lowest unoccupied molecular orbital(LUMO)level of-3.75 eV than that of one benzene unit based NFA IDT-4Cl and fluorene core based NFA F-2Cl,which facilitates enhancing the open-circuit voltage(V_(oc))of ternary devices.Moreover,TBF-2Cl film shows a medium optical bandgap with the absorption range from 500-800 nm,being well complementary with the wide bandgap polymer donor D18 and narrow bandgap NFA CH-6F.Accordingly,a remarkable PCE of 18.92%with a high short-circuit current density(J_(sc))of 27.40 mA·cm^(-2),a fill factor(FF)of 0.749,especially an outstanding V_(oc) of 0.922 V was achieved for the optimal ternary device based on D18:TBF-2Cl:CH-6F,surpassing the binary counterpart(17.08%).The findings provide insight into the development of new guest acceptors for obtaining more efficient OSCs.

Ternary organic solar cells:Improved optical and morphological properties allow an enhanced efficiency

The power co nversion efficiency(PCE)of OFQx-T:PC_(71)BM blend films reaches 7.59%.On this basis,ternary organic solar cells(OSCs)were fabricated with ITIC or PTB7-Th as the third component.The ternary OSCs with 50 wt%ITIC in acceptors exhibits an enhanced efficiency,from 7.59%to 8.17%.Also,the PCE of ternary OSCs with 50 wt%PTB7-Th in donors achieves 8.72%,which is 13%higher than that of binary OSCs.The PCE improvement of two ternary OSCs is mainly due to the increase of short-circuit current density(J_(SC)),which can be attributed to the complementary absorption spectra and improved film morphology.This work suggests that the selection of an appropriate third component plays a critical role in improving the PCE of ternary OSCs.