The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of...The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underlying 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6%with over 1000 h long-term operational stability.展开更多
The ancient aeolian sand has been regarded as an indicator for the formation and evolution of a desert in the past.Kumtagh Desert is located at the northern fringe of Qinghai-Tibet Plateau.The first integrated scienti...The ancient aeolian sand has been regarded as an indicator for the formation and evolution of a desert in the past.Kumtagh Desert is located at the northern fringe of Qinghai-Tibet Plateau.The first integrated scientific investigation to the desert was carried out during the period of 2004-2006.Kumtagh Desert is an ideal natural model for studying the formation and evolution of the desert because the Quaternary strata containing ancient aeolian sands are widely distributed.The integrated field investigation and studies on sedimentary,chronology and palynology of typical profiles named Suosuo gully,Xiaoquan gully and gravel body with ancient aeolian sand layers showed that Kumtagh Desert was probably formed as early as 2,097.7±314.7 ka BP.During the period of 386.9±58.0 ka BP to 285.9±42.9 ka BP,the desert largely expanded and formed its modern distribution pattern.The desert was originally developed in the southwest,subsequently,expanded to the north and northeast.The sedimentary facies of Suosuo gully profile revealed that the desert experienced at least 19 cycles of advance and inverse processes of desertification with an average period of 110 ka in the Quaternary.The neotectonic movements played an important role in the formation,development and geomorphology of the desert.On one hand,the movements caused the formation of intermontane fault basin,which was further developed towards the closed drought basin,and caused the formation of natural environment.On the other hand,under the control of surrounding faults,the unique broom-shaped desert landscape was formed,and the gullies and sand ridges in this region experienced an abrupt directional change from north by west to north by east at the location of 39°45＇-39°55＇N.The unique landscape of gravel body that occurred widely in the northern desert was formed after 285.9±42.9 ka BP.The results in this paper provide the scientific basis for studying the formation age and evolutionary process under the dry climate and environment in the northwestern China,and the uplifting of Qinghai-Tibet Plateau as well as its responses to the global climate changes.展开更多
With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water r...With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water resources cause the serious deterioration of ecological environment. According to the present ecoligical situation, by analyzing some actual problems of the ecosystem of Shiyang River Basin, a series of feasible control countermeasures are proposed. The article provide theoretical basis for the treatment and recovery of the degradation of ecological environment of Shiyang Rive Basin.展开更多
Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formu...Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formula as ABX3,where A is a monovalent cation such as methylammonium(CH3NH3,MA+)and formamidinium(HC(NH_(2)K,FA+),and B is a divalent metal cation such as Pb^(2+),and X is a halide(I,Br,Cl or their mixed)[4].展开更多
基金supported by the National Key Research and Development Program of China(2022YFB4200301)the National Natural Science Foundation of China(52202216)the Natural Science Foundation of Sichuan Province(24NSFSC1601).
文摘The use of low-dimensional(LD)perovskite materials is crucial for achieving high-performance perovskite solar cells(PSCs).However,LD perovskite films fabricated by conventional approaches give rise to full coverage of the underlying 3D perovskite films,which inevitably hinders the transport of charge carriers at the interface of PSCs.Here,we designed and fabricated LD perovskite structure that forms net-like morphology on top of the underlying three-dimensional(3D)perovskite bulk film.The net-like LD perovskite not only reduced the surface defects of 3D perovskite film,but also provided channels for the vertical transport of charge carriers,effectively enhancing the interfacial charge transfer at the LD/3D hetero-interface.The net-like morphological design comprising LD perovskite effectively resolves the contradiction between interfacial defect passivation and carrier extraction across the hetero-interfaces.Furthermore,the net-like LD perovskite morphology can enhance the stability of the underlying 3D perovskite film,which is attributed to the hydrophobic nature of LD perovskite.As a result,the net-like LD perovskite film morphology assists PSCs in achieving an excellent power conversion efficiency of up to 24.6%with over 1000 h long-term operational stability.
基金supported by Natural Science Foundation of Gansu Province (0803RJZH086)National Natural Science Foundation of China (40961013)
文摘The ancient aeolian sand has been regarded as an indicator for the formation and evolution of a desert in the past.Kumtagh Desert is located at the northern fringe of Qinghai-Tibet Plateau.The first integrated scientific investigation to the desert was carried out during the period of 2004-2006.Kumtagh Desert is an ideal natural model for studying the formation and evolution of the desert because the Quaternary strata containing ancient aeolian sands are widely distributed.The integrated field investigation and studies on sedimentary,chronology and palynology of typical profiles named Suosuo gully,Xiaoquan gully and gravel body with ancient aeolian sand layers showed that Kumtagh Desert was probably formed as early as 2,097.7±314.7 ka BP.During the period of 386.9±58.0 ka BP to 285.9±42.9 ka BP,the desert largely expanded and formed its modern distribution pattern.The desert was originally developed in the southwest,subsequently,expanded to the north and northeast.The sedimentary facies of Suosuo gully profile revealed that the desert experienced at least 19 cycles of advance and inverse processes of desertification with an average period of 110 ka in the Quaternary.The neotectonic movements played an important role in the formation,development and geomorphology of the desert.On one hand,the movements caused the formation of intermontane fault basin,which was further developed towards the closed drought basin,and caused the formation of natural environment.On the other hand,under the control of surrounding faults,the unique broom-shaped desert landscape was formed,and the gullies and sand ridges in this region experienced an abrupt directional change from north by west to north by east at the location of 39°45＇-39°55＇N.The unique landscape of gravel body that occurred widely in the northern desert was formed after 285.9±42.9 ka BP.The results in this paper provide the scientific basis for studying the formation age and evolutionary process under the dry climate and environment in the northwestern China,and the uplifting of Qinghai-Tibet Plateau as well as its responses to the global climate changes.
文摘With the increase of population and the development of social economy, contradiction between water supply and demand of Shiyang River Basin become more outstanding. Unreasonable exploitation and utilization of water resources cause the serious deterioration of ecological environment. According to the present ecoligical situation, by analyzing some actual problems of the ecosystem of Shiyang River Basin, a series of feasible control countermeasures are proposed. The article provide theoretical basis for the treatment and recovery of the degradation of ecological environment of Shiyang Rive Basin.
基金supported by the National Key Research and Development Program of China(2017YFA0207400)the National Natural Science Foundation of China(61604032,and 62004027)+4 种基金Sichuan Science and Technology Program(2019JDTD0006)the Fundamental Research Funds for the Central Universities of China(ZYGX2016J206)the China Postdoctoral Science Foundation(2019M663466)the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,and 21961160720)for financial support。
文摘Hybrid organic-inorganic perovskite solar cells(PSCs)have made rapid progress in efficiency from 3.8%to 25.5%in the past decade[1-3].The hybrid perovskite materials possess a 3D crystal structure with a chemical formula as ABX3,where A is a monovalent cation such as methylammonium(CH3NH3,MA+)and formamidinium(HC(NH_(2)K,FA+),and B is a divalent metal cation such as Pb^(2+),and X is a halide(I,Br,Cl or their mixed)[4].
