Perovskite solar cells are amongst the most exciting photovoltaic systems as they combine low recombination losses, ease of fabrication and high spectral tunability. The Achilles heel of this technology is the device stability due to the ionic nature of the perovskite crystal, rendering it highly hygroscopic, and the extensive diffusion of ions especially at elevated temperatures. Herein, we demonstrate the application of a simple solution-processed perfluorinated self-assembled monolayer (p-SAM) that not only passivates the perovskite surface but also drastically improves the stability of the perovskite absorber and in turn the solar cell under elevated temperature or humid conditions. p-i-ntype perovskite devices employing these SAMs exhibited power conversion efficiencies surpassing 21%. Notably, the best performing devices are stable under standardized maximum-power point (MPP) operation at 85°C in inert atmosphere (ISOS-L-2) for more than 250 h, and exhibit superior humidity resilience, maintaining ~95% device performance even if stored in humid air in the ambient over months (~3000h, ISOS-D-1). Our work, therefore, demonstrates a novel strategy towards efficient and stable perovskite solar cells with easily deposited functional interlayers.
Supporting Information.Experimental Methods, Supplementary Notes and Calculations, Details on Simulation, XRD, UV-Vis, XPS, FTIR, KP data, PL vs time, SPV measurements as well as additional experimental methods.
We study dissociative electron attachment to furan (FN) (C(4)H(4)O), tetrahydrofuran (THF) (C(4)H(8)O), and fructose (FRU) (C(6)H(12)O(6)) using crossed electron/molecular beams experiments with mass spectrometric detection of the anions. We find that FN and THF are weak electron scavengers and subjected to dissociative electron attachment essentially in the energy range above 5.5 eV via core excited resonances. In striking contrast to that, FRU is very sensitive towards low energy electrons generating a variety of fragment ions via a pronounced low energy feature close to 0 eV. These reactions are associated with the degradation of the ring structure and demonstrate that THF cannot be used as surrogate to model deoxyribose in DNA with respect to the attack of electrons at subexcitation energies (<3 eV). The results support the picture that in DNA the sugar moiety itself is an active part in the initial molecular processes leading to single strand breaks.
DNA origami nanostructures are used to arrange gold nanoparticles into dimers with defined distance, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). Single dye molecules (TAMRA and Cy3) can be placed into the SERS hot spots, with Raman enhancement up to 1010, which is sufficient to detect single molecules by Raman scattering.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.