Tailoring molecular termination for thermally stable perovskite solar cells

Interfacial engineering has made an outstanding contribution to the development of high-efficiency perovskite solar cells(PSCs).Here,we introduce an effective interface passivation strategy via methoxysilane molecules with different terminal groups.The power conversion efficiency(PCE)has increased from 20.97%to 21.97%after introducing a 3-isocyanatopropyltrimethoxy silane(IPTMS)molecule with carbonyl group,while a trimethoxy[3-(phenylamino)propyl]silane(PAPMS)molecule containing aniline group deteriorates the photovoltaic performance as a consequence of decreased open circuit voltage.The improved performance after IPTMS treatment is ascribed to the suppression of non-radiative recombination and enhancement of carrier transportation.In addition,the devices with carbonyl group modification exhibit outstanding thermal stability,which maintain 90%of its initial PCE after 1500 h exposure.This work provides a guideline for the design of passivation molecules aiming to deliver the efficiency and thermal stability simultaneously.

Dynamic evolution of nitrogen and oxygen dual-coordinated single atomic copper catalyst during partial oxidation of benzene to phenol

Single atom catalysts(SACs)with metal_(1)-N_(x)sites have shown promising activity and selectivity in direct catalytic oxidation of benzene to phenol.The reaction pathway is considered to be involving two steps,including a H_(2)O_(2)molecule dissociated on the metal single site to form the(metal_(1)-N_(x))=O active site,and followed by the dissociation of another H_(2)O_(2)on the other side of metal atom to form O=(metal_(1)-N_(x))=O intermediate center,which is active for the adsorption of benzene molecule via the formation of a C-O bond to form phenol.In this manuscript,we report a Cu SAC with nitrogen and oxygen dual-coordination(Cu1-N3O1 moiety)that doesn’t need the first H_(2)O_(2)activation process,as verified by both experimental and density function theory(DFT)calculations results.Compared with the counterpart nitrogen-coordinated Cu SAC(denoted as Cu1/NC),Cu SAC with nitrogen and oxygen dual-coordination(denoted as Cu1/NOC)exhibits 2.5 times higher turnover frequency(TOF)and 1.6 times higher utilization efficiency of H_(2)O_(2).Particularly,the coordination number(CN)of Cu atom in Cu1/NOC maintains four even after H_(2)O_(2)treatment and reaction.Combining DFT calculations,the dynamic evolution of single atomic Cu with nitrogen and oxygen dualcoordination in hydroxylation of benzene is proposed.These findings provide an efficient route to improve the catalytic performance through regulating the coordination environments of SACs and demonstrate a new reaction mechanism in hydroxylation of benzene to phenol reaction.

Discrimination of circular polarized light

The polarization control of light opens numerous explorations like information communication or three-dimensional displays.However,because the difference between number of left-handed and right-handed pho-tons in the free electromagnetic field is less than a per-cent,there is still a great challenge to measure the difference.

Polarization-insensitive interferometer based on a hybrid integrated planar light-wave circuit

Interferometers are essential elements in classical and quantum optical systems.The strictly required stability when extracting the phase of photons is vulnerable to polarization variation and phase shift induced by environment disturbance.Here,we implement polarization-insensitive interferometers by combining silica planar light-wave circuit chips and Faraday rotator mirrors.Two asymmetric interferometers with temperature controllers are connected in series to evaluate the single-photon interference.Average interference visibility over 12 h is above 99%,and the variations are less than 0.5%,even with active random polarization disturbance.The experiment results verify that the hybrid chip is available for high-demand applications like quantum key distribution and entanglement measurement.

Cross-boundary transport and source apportionment for PM_(2.5) in a typical industrial city in the Hebei Province,China:A modeling study

Cross-boundary transport of air pollution is a difficult issue in pollution control for the North China Plain.In this study,an industrial district(Shahe City)with a large glass manufactur-ing sector was investigated to clarify the relative contribution of fine particulate matter(PM_(2.5))to the city's high levels of pollution.The Nest Air Quality Prediction Model System(NAQPMS),paired with Weather Research and Forecasting(WRF),was adopted and applied with a spatial resolution of 5 km.During the study period,the mean mass concentrations of PM_(2.5),SO_(2),and NO_(2)were observed to be 132.0,76.1,and 55.5μg/m^(3),respectively.The model reproduced the variations in pollutant concentrations in Shahe at an acceptable level.The simulation of online source-tagging revealed that pollutants emitted within a 50-km radius of downtown Shahe contributed 63.4%of the city's total PM_(2.5)concentration.This contribu-tion increased to 73.9±21.2%when unfavorable meteorological conditions(high relative hu-midity,weak wind,and low planetary boundary layer height)were present;such conditions are more frequently associated with severe pollution(PM_(2.5)≥250μg/m^(3)).The contribution from Shahe was 52.3±21.6%.The source apportionment results showed that industry(47%),transportation(10%),power(17%),and residential(26%)sectors were the most important sources of PM_(2.5)in Shahe.The glass factories(where chimney stack heights were normally<70 m)in Shahe contributed 32.1%of the total PM_(2.5)concentration in Shahe.With an in-crease in PM_(2.5)concentration,the emissions from glass factories accumulated vertically and narrowed horizontally.At times when pollution levels were severe,the horizontally influ-enced area mainly covered Shahe.Furthermore,sensitivity tests indicated that reducing emissions by 20%,40%,and 60% could lead to a decrease in themass concentration of PM_(2.5) of of 12.0%,23.8%,and 35.5%,respectively.

Acrylamide fragment inhibitors that induce unprecedented conformational distortions in enterovirus 713C and SARS-CoV-2 main protease

RNA viruses are critically dependent upon virally encoded proteases to cleave the viral polyproteins into functional proteins.Many of these proteases exhibit a similar fold and contain an essential catalytic cysteine,offering the opportunity to inhibit these enzymes with electrophilic small molecules.Here we describe the successful application of quantitative irreversible tethering(qIT)to identify acrylamide fragments that target the active site cysteine of the 3C protease(3Cpro)of Enterovirus 71,the causative agent of hand,foot and mouth disease in humans,altering the substrate binding region.Further,we re-purpose these hits towards the main protease(Mpro)of SARS-CoV-2 which shares the 3C-like fold and a similar active site.The hit fragments covalently link to the catalytic cysteine of Mpro to inhibit its activity.We demonstrate that targeting the active site cysteine of Mpro can have profound allosteric effects,distorting secondary structures to disrupt the active dimeric unit.