Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling the nuts and bolts of solar hydrogen production. We report the use of Au@Cu₇S₄ yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable hydrogen production under visible and near infrared illumination. Ultrafast spectroscopic data reveal the prevalence of long-lived charge separation states for Au@Cu₇S₄ under both visible and near infrared excitation. Combined with the advantageous features of yolk@shell nanostructures, Au@Cu₇S₄ achieves a peak quantum yield of 9.4% at 500 nm and a record-breaking quantum yield of 7.3% at 2200 nm for hydrogen production in the absence of additional co-catalysts. The design of a sustainable visible- and near infrared-responsive photocatalytic system is expected to inspire further widespread applications in solar fuel generation. In this work, the feasibility of exploiting the localized surface plasmon resonance property of self-doped, nonstoichiometric semiconductor nanocrystals for the realization of wide-spectrum-driven photocatalysis is highlighted.

To solve the toxic issue for new-generation photovoltaic applications, tin-based perovskite solar cells are a promising alternative to their lead counterparts, but they suffer from poor stability because of their tendency to exhibit tin oxidation. Herein we report a new sequential method of deposition based on solution processing using hexafluoro-2-propanol as a solvent to deposit eight bulky ammonium cations on top of the 3D layer to form a 3D/quasi-2D layer to protect the tin perovskite grains from penetration by moisture. The formation of the 2D layer was confirmed with grazing-incidence wide-angle X-ray scattering, scanning electron microscopy, conducive atomic force microscopy, photoluminescence, and transient absorption spectroscopy measurements. The anilinium (AN) device showed a remarkable performance with an efficiency of 10.6% and with great stability in ambient air without encapsulation. The AN device also showed a self-healing effect of performance when it was subjected to a severe environment under continuous light soaking in one-sun illumination and thermal stress between 20 and 50 °C for 10 cycles.

CoO_x is a promising hole-extracting layer (HEL) for inverted planar perovskite solar cells with device configuration ITO/CoO_x/CH₃NH₃PbI₃/PCBM/Ag. The devices fabricated according to a simple solution procedure showed the best photovoltaic performance attaining power conversion efficiency (PCE) 14.5 % under AM 1.5 G one-sun irradiation, which is significantly superior to those fabricated with a traditional HEL such as PEDOT:PSS (12.2 %), NiOx (10.2 %) and CuOx (9.4 %), under the same experimental conditions. We characterized the chemical compositions with XPS, crystal structures with XRD and film morphology with SEM/AFM techniques. Photoluminescence (PL) spectra and the corresponding PL decays for perovskite deposited on varied HEL films were recorded to obtain the hole-extracting characteristics, for which the hole-extracting times show the order CoO_x (2.8 ns) < PEDOT:PSS (17.5 ns) < NiO_x (22.8 ns) < CuO_x (208.5 ns) consistent with the trend of their photovoltaic performances. The reproducibility and enduring stability of those devices were examined to show the outstanding long-term stability of the devices made of metal oxide HEL, for which the CoO_x device retained PCE ~ 12 % for over 1000 h.