Selenophene-containing benzodithiophene based donors with different alkyl chains in terminal groups for high-performance all-small-molecule organic solar cells

Abstract

Two small molecule (SM) donors, named CBTSeHR and CBTSeEHR, have been constructed by introducing selenophenes and chlorine atoms into the conventional benzodithiophene-terthiophene-rhodanine architecture simultaneously. In comparison to non-chlorinated and thiophene...

A nonfullerene acceptor with π-conjugation extended end groups to achieve enhanced photovoltaic performance

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] Recently, the rapid development of NFAs was mainly dominated by acceptor-donor-acceptor (A-D-A) type small-molecule acceptors (SMAs), [15][16][17][18][19][20][21][22][23][24][25][26][27] The main reason for great success of the A-D-A type SMAs lies in their easilytuned optoelectronic properties through simple chemical modification on the D and A units. [28][29][30][31][32][33][34][35][36][37] Elegant works have been reported, such as modulating the central units (D) with varied side chains to adjust the crystalline properties and modifying the terminal units (A) by introducing different functional groups to tune the light absorption range and molecular energy level, thus leading to a significant impact on the short-current density ( J sc ), open-circuit voltage (V oc ) and fill factor (FF). [38][39][40][41][42][43] As is well known, the introduction of electron-withdrawing groups or electron-donating groups on terminal units is a popular and efficient way to...…”

Ternary organic solar cells with a selenophene-containing donor guest achieve a high efficiency of 18.41%

“…1a, which exhibits high photovoltaic performance in all-small-molecule OSCs. 49 From the optical property point of view, CBTSeHR shows an absorption band of 400-700 nm with the maximum absorption peak (l max ) at B580 nm, benefiting from the introduction of the selenophene unit, which is red-shifted by B22 nm compared with the thiophene based donor, and more complementary with the star materials, such as wide bandgap polymer donors poly[dithieno [3,2-…”

“…1a, which exhibits high photovoltaic performance in all-small-molecule OSCs. 49 From the optical property point of view, CBTSeHR shows an absorption band of 400–700 nm with the maximum absorption peak ( λ max ) at ∼580 nm, benefiting from the introduction of the selenophene unit, which is red-shifted by ∼22 nm compared with the thiophene based donor, and more complementary with the star materials, such as wide bandgap polymer donors poly[dithieno[3,2- e :2′,3′- g ]-2,1,3-benzothiadiazole-5,8-diyl[4-(2-butyloctyl)-2,5-thiophenediyl][4,8-bis[5-(2-ethylhexyl)-4-fluoro-2-thienyl]benzo[1,2- b :4,5- b ′]dithiophene-2,6-diyl][3-(2-butyloctyl)-2,5-thiophenediyl]] (D18), PM6 and narrow bandgap Y-series NFAs. In addition, CBTSeHR possesses a low-lying highest occupied molecular orbital (HOMO) energy level, which contributes to forming the cascaded energy levels with the prevailing polymer donors and SM NFAs, thus promoting charge transport and the enhancement of V oc for ternary OSCs.…”

Regulating Crystallinity and Miscibility via Ternary Strategy Triggers Efficient All-Small-Molecule Organic Solar Cells

“…Figure a presents molecular structures of FSBTSeHR, B1, and BTP-eC9. FSBTSeHR has a similar molecular structure to B1, whereas the benzene ring and thiophene on the side chain were replaced by F-thiophene and selenophenol, respectively, which enhance the molecular crystallinity. , The molecular packing morphology of B1 and BTP-eC9 was measured by grazing-incidence wide-angle X-ray scattering (GIWAXS). As shown in Figure S1, multiple lamellar diffraction peaks in the out-of-plane (OOP) direction are exhibited in the B1 film, along with a π–π stacking (010) diffraction peak in the (in-plane) IP direction, suggesting an edge-on-dominated molecular orientation.…”