Excess PbI_(2)evolution for triple-cation based perovskite solar cells with 21.9%efficiency

The triple cation mixed perovskites(Cs FAMA)are known as one of the most efficient candidates for perovskite solar cells(PSCs).It is found that the power conversion efficiency(PCE)of triple-cation based devices would increase with the test time extending,and the maximum efficiency is normally obtained after several days aging storage.Here,the relationship between enhanced device performance,excess PbI_(2)and its evolution in triple cation perovskite films of initial days was systematically explored.The Cs FAMA-PSCs are prepared by two-step methods under two environmental conditions,including in the glove box and the ambient air(30%humidity).After 7 days testing,the maximum PCE of PSCs under two conditions dramatically increased 12.4%and 12.2%,reached 21.68%and 21.89%,respectively.At initial days,the XRD peak intensities of perovskite phase gradually decreased and those corresponding to PbI_(2)increased.Along with time-resolved photoluminescence(TRPL)and kelvin probe force microscopy(KPFM),it was found that the defects were passivated with the evolution of PbI_(2).This work reveals the excess PbI_(2)and its evolution in perovskite film,which can further supplement the understanding of PbI_(2)defect passivation.

Single-dose AAV-based vaccine induces a high level of neutralizing antibodies against SARS-CoV-2 in rhesus macaques

Dear Editor,Coronavirus disease 2019(COVID-19)is a highly infectious respiratory disease that continues to pose a serious global public health emergency.The disease shows a high infection rate,long incubation period,and rapidly emerging variants,which have led to its rapid spread worldwide(Krammer 2020).Many vaccines have been developed for the control of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the virus responsible for COVID-19,including vaccines based on messenger RNA(mRNA)(Polack et al.2020),viral vectors(Zhu et al.2020),recombinant proteins(Yang et al.2020),and inactivated SARS-CoV-2(Zhang et al.2021).

Recombinant chimpanzee adenovirus vector vaccine expressing the spike protein provides effective and lasting protection against SARS-CoV-2 infection in mice

SARS-CoV-2 infection is a global public health threat.Vaccines are considered amongst the most important tools to control the SARS-CoV-2 pandemic.As expected,deaths from SARS-CoV-2 infection have dropped dramatically with widespread vaccination.However,there are concerns over the duration of vaccine-induced protection,as well as their effectiveness against emerging variants of concern.Here,we constructed a recombinant chimpanzee adenovirus vectored vaccine expressing the full-length spike of SARS-CoV-2(Ad C68-S).Rapid and high levels of humoral and cellular immune responses were observed after immunization of C57BL/6J mice with one or two doses of Ad C68-S.Notably,neutralizing antibodies were observed up to at least six months after vaccination,without substantial decline.Single or double doses Ad C68-S immunization resulted in lower viral loads in lungs of mice against SARS-CoV-2 challenge both in the short term(21 days)and long-term(6 months).Histopathological examination of Ad C68-S immunized mice lungs showed mild histological abnormalities after SARS-CoV-2 infection.Taken together,this study demonstrates the efficacy and durability of the Ad C68-S vaccine and constitutes a promising candidate for clinical evaluation.

Infection and pathogenesis of the Delta variant of SARS-CoV-2 in Rhesus macaque

Dear Editor,COVID-19 caused by SARS-Co V-2,is still a big threat to human populations around the world.As of Jan 2022,over 292 million cases were reported worldwide with more than 5.4 million deaths.After it was first reported in China in December 2019,the virus kept circulating and evolving and several variants with different transmissibility emerged in different countries and regions(WHO,2021a).