Designing benzothiadiazole based non-fullerene acceptors with high open circuit voltage and higher LUMO level to increase the efficiency of organic solar cells

Designing of small molecule non-fullerene acceptors with cyanobenzene core for photovoltaic application

Four acceptor-donor-acceptor (A-D-A) type cyclopentadithiophene core-based non-fullerene small acceptor molecules were designed with the objective to improve the proficiency of photovoltaic cells. A comprehensive density functional theory (DFT) analysis was done by employing B3LYP functional with 6-31G(d,p) basis set to study optoelectronic properties of R as well as M1-M4 molecules, while the time-dependent self-consistent field (TDSCF) was utilized to analyze their excited state calculations. Several essential characteristics must be refined in order to enhance the efficiency of small molecular acceptors, i.e., the density of states (DOS), HOMO-LUMO band gap, transition density matrix (TDM), dipole moment, reorganization energy, light-harvesting efficiency, and open-circuit voltage, etc. In comparison to the R molecule, all the derived molecules show better maximum absorption (in chloroform solvent) with a range of 886-951 nm and a smaller band gap with a range of 1.65-1.55 eV M2 retains the least exciton binding energy of 0.24 eV, and amongst all the investigated molecules M3 molecule has the least interaction coefficient values so, it possesses better charge transport probability. The reorganization energy values in eV for both electron (0.00579) and hole (0.00737) are the least for M3 molecule, so this molecule exhibits better charge mobility for electron and hole. VOC of R and M1-M4 molecule was calculated by theoretically computing the values of their complexes with PTB7-Th donor molecule. 

End-capped group modification on cyclopentadithiophene based non-fullerene small molecule acceptors for efficient organic solar cells; a DFT approach.

With the aim of upgrading the power conversion efficiency of organic solar cells (OSCs), four novel non-fullerene, A1-A2-D-A2-A1-type small molecules were designed that are derivatives of a recently synthesized molecule SBDT-BDD reported for its efficient properties in all-small-molecule OSCs (ASM-OSCs). Optoelectronic properties of the designed molecules were theoretically computed with a selected CAM-B3LYP functional accompanied by the 6-31G(d,p) basis set of density functional theory (DFT), and excited-state calculations were performed through the time-dependent self-consistent field. The parameters of all analyzed molecules describing the charge distribution (frontier molecular orbitals, density of states, molecular electrostatic potential), absorption properties (UV-vis absorption spectra), exciton dynamics (transition density matrix), electron-hole mobilities (reorganization energies), and exciton binding energies were computed and compared. All the designed molecules were found to be superior regarding the aforesaid properties to the reference molecule. Among all molecules, SBDT1 has the smallest band gap (3.88 eV) and the highest absorption maxima with broad absorption in the visible region. SBDT3 has the lowest binding energy (1.51 eV in chloroform solvent) ensuring easier and faster dissociation of excitons to produce free charge-carriers and has the highest open-circuit voltage (2.46 eV) with PC61BM as the acceptor. SBDT1 possesses the highest hole mobility because it has the lowest value of λ+ (0.0148 eV), and SBDT4 exhibits the highest electron mobility because it has the lowest value of λ- (0.0146 eV). All the designed molecules are good candidates for ASM-OSCs owing to their superior and optimized properties.

Tuning of a A-A-D-A-A-Type Small Molecule with Benzodithiophene as a Central Core with Efficient Photovoltaic Properties for Organic Solar Cells.

Designing and theoretical characterization of benzodithiophene dione based donor molecules for small molecule organic solar cells

In this paper, four small molecules B1, B2, B3 and B4 based on donor–acceptor–donor–acceptor–donor (D-A-D-A-D) combination were designed by making structural modifications in R. The designed molecu...

Designing of 5,10-Dihydroindolo [3,2-b] Indole (DINI) Based Donor Materials for Small Molecule Organic Solar Cells

Nutritional status is an important aspect of child’s health profile and affects child’s development and growth. This study aimed at exploring relationship between maternal literacy and malnutrition in children under-five years old. Methodology: Two groups were made comprising of mothers, according to the nutritional status of their under-five children presenting in free clinic in Ali Raza Abad Lahore with URTI. Results: Significant difference was found in literacy level in two groups; with 38% illiteracy amongst mothers with malnourished children as compared to 14% amongst women with children not suffering from malnutrition and p value at 0.0062. More mothers of children suffering from malnutrition were found illiterate as compared to mother of well-nourished children. Conclusion: As illiteracy affected children nutrition it is recommended that illiterate women may be targeted for health education on short term basis and education be made mandatory for long term solution to this problem.

https://ppmj.org.pk/index.php/ppmj/article/download/128/252

Arooj Fatima

Papers

Designing of 5,10-Dihydroindolo [3,2-b] Indole (DINI) Based Donor Materials for Small Molecule Organic Solar Cells

Maternal literacy and malnutrition in children: A comparative study.