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Query: UMLS:C1832588 (PSS)
 2,979 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Herein, solvent-treated bandgap-tunable covalent organic nanosheets (CONs) were prepared via the Stille cross-coupling reaction. These materials are considered useful as interlayers in photovoltaic devices upon the alignment of energy levels between other components. Among various types of solar cells, according to the organic-interlayer study, inverted planar perovskite solar cells (PSCs) are mostly demanded to effectively transport and collect charge carriers due to their high performance. At first, the C-V analysis proved the energy levels of the frontier orbitals for CON-10 and CON-16 nanosheets; this verified the suitability of these nanosheets as hole transport layers (HTLs) with the PEDOT:PSS upon casting both films from DMSO. It became evident, however, that the hole transport property of the PEDOT:PSS on the CON-16 layer was unfavorable with the increasing UPS-proven hole injection barrier. In addition, both CONs induced a rough surface morphology; however, CON-10 showed a relatively smooth surface as compared to CON-16 based on the Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) profiles; furthermore, their surface properties influenced both the PEDOT:PSS layers and the perovskite layers. Especially, the XRD profiles presented an enhanced crystallinity of the perovskite layers with CON-10. All these aspects indicate that CON-10 is a more effective HTL material, and several versions of perovskite solar cells (PSCs) have been fabricated with/without CON-10 and CON-16 together with the PEDOT:PSS to determine the more-HTL-suitable CON. As a result, the power conversion efficiencies (PCEs) of the optimized devices with CON-10 exhibited a value of 10.2%, which represented a 1% increase over those of the reference devices without the CONs and was 4% higher than that of the CON-16 devices. Moreover, the devices with CON-10 were further optimized with TiOx using Al electrodes, leading to a PCE increase of these devices that became slightly higher than the PCEs of the device with CON-10 and without TiOx. This tendency was supported by photoluminescence (PL) spectroscopy, photocurrent density (Jph), and space-charge-limited current (SCLC) mobility results.
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PMID:Covalent organic nanosheets for effective charge transport layers in planar-type perovskite solar cells. 2945 80

Due to the low temperature fabrication process and reduced hysteresis effect, inverted p-i-n structured perovskite solar cells (PSCs) with the PEDOT:PSS as the hole transporting layer and PCBM as the electron transporting layer have attracted considerable attention. However, the energy barrier at the interface between the PCBM layer and the metal electrode, which is due to an energy level mismatch, limits the electron extraction ability. In this work, an inorganic aluminum-doped zinc oxide (AZO) interlayer is inserted between the PCBM layer and the metal electrode so that electrons can be collected efficiently by the electrode. It is shown that with the help of the PCBM/AZO bilayer, the power conversion efficiency of PSCs is significantly improved, with negligible hysteresis and improved device stability. The UPS measurement shows that the AZO interlayer can effectively decrease the energy offset between PCBM and the metal electrode. The steady state photoluminescence, time-resolved photoluminescence, transient photocurrent, and transient photovoltage measurements show that the PSCs with the AZO interlayer have a longer radiative carrier recombination lifetime and more efficient charge extraction efficiency. Moreover, the introduction of the AZO interlayer could protect the underlying perovskite, and thus, greatly improve device stability.
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PMID:Improving Electron Extraction Ability and Device Stability of Perovskite Solar Cells Using a Compatible PCBM/AZO Electron Transporting Bilayer. 3021 19