Crystallization driven boost in fill factor and stability in additive-free organic solar cells

Abstract

The control of morphology and microstructure during and after the active layer processing of bulk-heterojunction solar cells is critical to obtain elevated fill factors and overall good device performance. With...

Effects of the diphenyl ether additive in halogen-free processed non-fullerene acceptor organic solar cells

“…Both spectra display the typical acceptor emission, while the emission from the donor is totally quenched. 34,35 Comparing the two spectra, the addition of DPE leads to slightly increased PL intensity, together with a redshift of the peak, which is consistent with that observed for the absorption spectra.…”

“…Similar transient spectra have been reported for analogous donor:acceptor blend systems. 34,36 Despite the fact that the 700 nm wavelength used to excite the blend is above the edge of absorption of the donor, located around 650 nm, 34,35 a photobleaching of its ground state is observed in both blend films, confirming a fast hole transfer following the exciton generation in the acceptor. The comparison of the transient spectra at different times after excitation reveals a difference in the evolution of the donor signal and, thus, in the charge carrier dynamics, when DPE is used.…”

“…1c) show the characteristic absorption features of TPD-3F with peaks around 560 and 610 nm, and IT-4F with a peak at 720 nm. 34,35 The most noteworthy change in the absorption spectrum, due to the use of DPE, is an increased absorption in the spectral range of the donor material with respect to the peak of the acceptor, which suggests an effect of the additive in the formation of the donor-rich domains. A closer look at the absorption peak of the acceptor, as reported in the inset of Fig.…”

Solution-Processed Self-Powered Panchromatic Organic Photodiode and Its Application in Biomedical Devices

“…The J sat value for device D1 is found to be 0.34 mA/cm 2 , which is lower than the value of 0.61 mA/cm 2 obtained for device D3. The charge collection probabilities ( P c ) is evaluated from the ratio at 0 V for the devices. , The estimated P c values (Figure S3b and Table S2) are 85.40%, 95.10%, and 94.20% for devices D1, D2, and D3 respectively. When the photoactive layer thickness is changed from 95 to 215 nm, both photocurrent density and P c increased, while further increment to 310 nm has resulted in a slight decrement of both photocurrent density and P c .…”

Efficient Ternary Polymer Solar Cells Employing Well Matched Medium Band Gap and Narrow Band Gap Nonfullerene Acceptors

“…The increased CCL values in the optimized ternary film indicate higher molecular crystallinity of the film. The increased molecular crystallinity and compact π–π stacking distance is advantageous for charge transport in ternary active layer which is well consistence with enhanced FF for ternary PSC. , …”