A Cross‐Linked Interconnecting Layer Enabling Reliable and Reproducible Solution‐Processing of Organic Tandem Solar Cells

Abstract

The performance of tandem organic solar cells (OSCs) is directly related to the functionality and reliability of the interconnecting layer (ICL). However, it is a challenge to develop a fully functional ICL for reliable and reproducible fabrication of solution‐processed tandem OSCs with minimized optical and electrical losses, in particular for being compatible with various state‐of‐the‐art photoactive materials. Although various ICLs have been developed to realize tandem OSCs with impressively high performance, their reliability, reproducibility, and generic applicability are rarely analyzed and reported so far, which restricts the progress and widespread adoption of tandem OSCs. In this work, a robust and fully functional ICL is developed by incorporating a hydrolyzed silane crosslinker, (3‐glycidyloxypropyl)trimethoxysilane (GOPS), into poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and its functionality for reliable and reproducible fabrication of tandem OSCs based on various photoactive materials is validated. The cross‐linked ICL can successfully protect the bottom active layer against penetration of high boiling point solvents during device fabrication, which widely broadens the solvent selection for processing photoactive materials with high quality and reliability, providing a great opportunity to continuously develop the tandem OSCs towards future large‐scale production and commercialization.

Chemical Coupled PEDOT:PSS/Si Electrode: Suppressed Electrolyte Consumption Enables Long-Term Stability

“…After treating with GOPS, the PSS region's S 2p spectra relate to the -SO 3 − groups interacting with Na + or H + (~ 169 eV) has a shift to higher binding energy, while the PSS interacting with PEDOT and PEDOT region stays constant. The XPS revealed the cross-linking between PEDOT:PSS and GOPS [32][33][34]. The O 1s spectra after treating with GOPS also showed a shift to high binding energy ( Fig.…”

Recent Advances of Synthesis, Properties, Film Fabrication Methods, Modifications of Poly(3,4‐ethylenedioxythiophene), and Applications in Solution‐Processed Photovoltaics

“…This make it easy to be chemically passivated by adopting ion exchange strategy [19,266] or chemical cross-linking approach. [267] The large organic cations in ionic liquids (ILs) can exchange with the protons of PSS, leading to the transition of ionic bond of SO 3…”

“…[268] Both effects contribute to the improved water resistance of PEDOT:PSS:GOPS films. [267] The hydroxyl groups in poly(ethylene glycol) methyl ether (PEGME) can react with -SO 3 − in PSS via esterification reaction. The crosslinked PEDOT:PSS:PEGME layer become less hygroscopic.…”

Recent Developments in Organic Tandem Solar Cells toward High Efficiency

“…[ 30 ] Similarly, the introduction of efficient transporting and recombination materials in OTSCs could be a competent approach toward minimizing V OC loss. [ 31–33 ] Moreover, a proper design of energy levels of organics will encourage V OC as well. In this case, the difference between the highest occupied molecular orbitals (HOMO) of the donating materials and lowest unoccupied molecular orbital (LUMO) of the acceptor is proportional to V OC .…”