Tuning the molecular geometry and packing mode of non-fullerene acceptors by altering the bridge atoms towards efficient organic solar cells

Abstract

<p>Altering only one atom in a fused-ring changes the molecular geometry and thus impacts the optoelectronic properties and device performance.</p>

Exploration of the Intriguing Photovoltaic Behavior for Fused Indacenodithiophene-Based A–D–A Conjugated Systems: A DFT Model Study

“…As illustrated in Table 1 , the calculated HOMO and LUMO energies of IDICR are −5.948 and −3.703 eV, comprising a band gap of 2.245 eV, comparable with the experimental value (1.77 eV). 28 This good agreement points out that the implemented DFT computation, i.e., B3LYP functional, is suitable for use to investigate IDIC1–IDIC6. The HOMO energy values of IDIC1, IDIC2, IDIC3, IDIC4, IDIC5, and IDIC6 are calculated to be −6.018, −6.233, −6.265, −5.944, −6.008, and −6.628 eV, respectively.…”

“…There is good agreement between the absorption values of the simulated and experimental results (668 nm). 28 Among all designed molecules, the lower λ max has been observed in the case of IDIC1 when the −CN group of IDICR is replaced with a nitro group. This further enhancement in λ max is examined in IDIC1–IDIC5 when two halo groups are introduced on the terminal benzene ring of the acceptor.…”

“…The distribution pattern of FMOs provides helpful visuals and numbers for the characterization of photovoltaic and optoelectronic behavior of chromophores in OSCs. 29 Intermolecular charge transfer (ICT), chemical stability, reactivity, and molecular interactions also come under the scope of FMOs 30 and can be well explained through this tool. 31 Pictorial representation of the molecular orbitals of all studied chromophores at the B3LYP/6-311G(d,p) level of theory is exhibited in Figure 3 , and computed results are tabulated in Table 1 .…”

“… 25 Moreover, the extended π-conjugation with fullerene-free compounds with intense absorption parameters has been improved via attachment with fluoro, 26 cyano, and chloro units over the NFA skeleton. 27 In this article, we have designed seven new A–D–A-type chromophores, namely, IDIC1 – IDIC6 , from a reference compound IDIC-C8 ( 28 ) represented as IDICR . All of the new compounds have been designed by changing the terminal acceptor unit of reference chromophores containing two 2-(2,3-dihydro-3-oxo-1 H -inden-1-ylidene) propanedinitrile (IC) units attached at the terminal with an electron-donating core, indacenodithiophene ( IDT ).…”

Impact of packing arrangement on the optical properties of C60 cluster aggregates

“…Materials made from organic π -conjugated molecules (for instance, fullerenes and their derivatives) 1–3 have attracted much attention over the past few years as the active components in optoelectronic devices including field-effect transistors, solar cells, and light-emitting diodes, to mention a few examples. Among fullerenes, C60 buckminsterfullerene has attracted much attention due to its application in new bulk heterojunction organic solar cells 4–15 due to the unique properties, including high electron mobility, suitable band gaps, and good compatibility with other semiconducting materials. In a related context, optical excitations in π -conjugated molecules depend strongly on the packing configuration of the basic building blocks.…”