Non-fullerene acceptors (NFAs) dominate organic photovoltaic (OPV) research due to their promising efficiencies and stabilities. However, there is very little investigation into the molecular processes of degradation, which is critical to guiding design of novel NFAs for long-lived, commercially viable OPVs. Here we investigate the important role o...
Controlling initial bulk-heterojunction (BHJ) morphology is critical for device performance of organic photovoltaic (OPV) cells. However, its impact on performance, specifically long-term operational stability is still poorly understood. This is mainly due to limitations in direct measurements enabling in-situ monitoring of devices at a molecular l...
status: published
Regio-regular poly(3-hexylthiophene-2,5-diyl) (rr-P3HT), the work-horse of organic photovoltaics, has been recently exploited in bulk heterojunction (BHJ) configuration with phenyl-C61-butyric acid methyl ester (PCBM) for solution-processed hydrogen-evolving photocathodes, reaching cathodic photocurrents at 0 V vs. RHE (J0V vs RHE) of up to 8 mA cm...
Using drift-diffusion simulations, we investigate the voltage dependence of the dark current in single carrier devices, typically used to determine charge-carrier mobilities. For both low and high voltages, the current increases linearly with the applied voltage. Whereas the linear current at low voltages is mainly due to space charge in the middle...
Extracting charge-carrier mobilities for organic semiconductors from space-charge-limited conduction measurements is complicated in practice by nonideal factors such as trapping in defects and injection barriers. Here, we show that by allowing the bandlike charge-carrier mobility, trap characteristics, injection barrier heights, and the shunt resis...
Here we elucidate the nanostructure–property relationships in low-temperature, solution-processed ZnO based thin films employed as novel electron transport layers (ETLs) in organic photovoltaic (OPV) devices. Using a low-cost zinc precursor (zinc acetate) in a simple amine–alcohol solvent mix, high-quality ETL thin films are prepared. We show that ...
We describe an effective means of defining optimisation criteria for self-optimising reactors, applicable to situations where a compromise is sought between several competing objectives. The problem is framed as a constrained optimisation, in which a lead property is optimised subject to constraints on the values that other properties may assume. C...
Two regioisomeric D-1-A-D-A-D-1 type pi-conjugated molecules (1,4-bis{5-[4-(5-fluoro-7-(5-hexylthiophen-2-yl) benzo[c][1,2,5] thiadiazole)] thiophen-2-yl}-2,5-bis(hexyldecyloxy) benzene (Prox-FBT) and 1,4-bis{5-[4-(6-fluoro-7-(5-hexylthiophen-2-yl) benzo[c][1,2,5] thiadiazole)] thiophen- 2-yl}-2,5-bis(hexyldecyloxy) benzene (Dis-FBT)) are synthesiz...
The control of the molecular energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is crucial to the design of highly efficient polymer solar cells (PSCs). In particular, the fine control of the HOMO energy level is vital because it can ensure that polymer solar cell devices have a high op...
