Plasma modification of poly(2-heptadecyl-4-vinylthieno[3,4-d]thiazole) low bandgap polymer and its application in solar cells

Abstract

For the first time, we here propose a green methodology to modify a low bandgap polymer for highly efficient solar cells using atmospheric pressure plasma jet or soft plasma operating on different feeding gases (air, Ar and N 2 ). The physical properties of the modified polymer were investigated using conductivity measurements, UV-visible spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammograms, atomic force microscopy, cathodoluminescence and confocal Raman spectroscopy. Further, we examined the variation of the work function of the polymer before and after plasma treatment using a g-focused ion beam. Additionally, photovoltaic cells based on the plasma-modified polymer having ITO/PEDOT:PSS/PHVTT (with or without plasma modification):PC 71 BM/LiF/Al configuration were fabricated and then characterized. We found that the power conversion efficiency (PCE) of the plasma-modified polymer increased dramatically as compared to the control polymer (without plasma treatment). PCE of the control polymer was found to be 4.11%, while after air, Ar and N 2 gas plasma treatment the polymer showed PCEs of 4.85%, 4.87% and 5.14% respectively. Thus, plasma treatment not only alters the surface properties, but also modifies the bulk properties (changes in HOMO and LUMO bandgap level). Hence, this work provides new dimensions to explore more about plasma and polymer chemistry.

A comparative study for the inactivation of multidrug resistance bacteria using dielectric barrier discharge and nano-second pulsed plasma

“…In this study, we investigated the changes in carbon (C 1s) and oxygen (O 1s) after the plasma treatment. All XPS peaks were examined according to those reported in prior studies 13 14 33 34 .…”

“…The C 1s and O 1s core level spectrum of the S. aureus (wild type) and multidrug resistant bacteria (PRSA, MRSA and GRSA) are shown in Figures S5-S12 . The binding energies were corrected by taking the C 1s core level at 284.6 eV for all samples 13 14 35 . The carbon 1s XPS spectra show signals at 284.6, 286.02, 287.06 and 289.04 eV, respectively, which correspond to the C–C/C-H, C–O and C=O functional groups of bacteria in wild type and in drug resistant bacteria.…”

“…Atmospheric pressure non-thermal plasma (APP) provides a means to efficiently and effectively control multidrug resistant microorganisms 9 10 . Depending on the sources and discharge conditions, APP is an efficient source of a combination of electronically excited atoms, charged particles (electrons, ions), ozone (O 3 ), UV photons and radicals 9 10 11 12 13 14 15 16 17 18 19 . APP has shown great promise for use to sterilize medical products and packaging materials since it effectively inactivates bacteria and bacterial spores, besides of material modification 9 10 11 .…”

Enhancing performance of inverted planar perovskite solar cells by argon plasma post-treatment on PEDOT:PSS

“…8 A higher conductivity caused by the removal of PSS concentration from XPS analysis may contribute to the improved J sc . The signicantly increased value of V oc could be explained by the changing of HOMO and LUMO band gap level presented by Attri, et al, 25 which leads to a restrained charge recombination. It should be noticed that, the devices based on PEDOT:PSS layer treated by 4 min and 5 min exhibit reduced efficiency of 11.29% and 10.34%, which are still higher than the efficiency of devices based on pristine PEDOT:PSS layer.…”

Interaction Studies between Newly Synthesized Photosensitive Polymer and Ionic Liquids

“…Confocal Raman microscopy is a more sophisticated technique; it estimates the vibrational energy of target solutes and eliminates the need of invasive monitoring aids [33][34][35]. However, owing to the penetration of the polymeric membrane, the Raman signal was strongly diminished and the excited laser's signal was also strongly attenuated.…”