Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs_(2)P...Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs_(2)Pb(SCN)_(2)Br_(2) has been reported that opens up new potential for the development of 2D RP perovskites.However,recent reports of unusual dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2) have generated intense debate about its origin and remains controversial.Here,by combining continuous pressure tuning with in situ diagnostics,we have unambiguously revealed the underlying mechanisms that the 2D Cs_(2)Pb(SCN)_(2)Br_(2) exhibits an intrinsic blue emission at 2.66 eV and an absorption edge close to the emission peak.While the gradually formed CsPbBr3 is responsible for the green emission at 2.33 eV with the absorption shoulder at 2.41 eV.Furthermore,by fitting the temperature-dependent intensity of the intrinsic blue emission,we have determined the corrected value of exciton binding energy for 2D Cs_(2)Pb(SCN)_(2)Br_(2) to be 90 meV.Intriguingly,an emission enhancement of 2.5 times is achieved in Cs_(2)Pb(SCN)_(2)Br_(2) under a mild pressure within 0.8 GPa,caused by the pressuresuppressed exciton-phonon interaction.This work not only elucidates the origin of the dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2),but it also provides a potential means to regulate and optimize the optoelectronic properties of 2D perovskites.展开更多
Carbolong compounds as a metal-heteroaromatic compound with both organometallic properties andπ-conjugated systems exhibit great potential in organic catalysis and optoelectronic devices.In this work,for the first ti...Carbolong compounds as a metal-heteroaromatic compound with both organometallic properties andπ-conjugated systems exhibit great potential in organic catalysis and optoelectronic devices.In this work,for the first time,the“Bucket Effect”is revealed to promote the third-order nonlinear optical(NLO)performance in metal-heteroaromatic compounds.We have successfully constructed and investigated a series of novel metallapentalenes with higher third-order NLO performance benefited from the“Bucket Effect”.Meanwhile,aromaticity and electron−hole analysis further confirm the internal homogeneity of organometallic rings,reduced bandgap,and enhanced low-energy peak response resulted in the enhanced third-order NLO effects.The success of this work is discovering an emerging material library of high third-order NLO effects,and illustrating the feasibility of engineering the high response metal-heteroaromatic optical devices at the electronic structure level.展开更多
基金supported by the National Natural Science Foundation of China (NSFC) (grant nos.22275004,U1930401,and 52325309)the Shanghai Science and Technology Committee (grant no.22JC1410300)+1 种基金the Shanghai Key Laboratory of Novel Extreme Condition Materials (grant no.22dz2260800)supported by the NSFC (grant no.22275077).Q.H.is supported by the CAEP Research (grant no.CX20210048)and the Tencent Xplorer Prize (grant no.XPLORER-2020-1013).
文摘Two-dimensional(2D)Ruddlesden-Popper(RP)halide perovskites with diverse structures and properties have drawn increasing attention due to their promising optoelectronic applications.Recently,a new all-inorganic Cs_(2)Pb(SCN)_(2)Br_(2) has been reported that opens up new potential for the development of 2D RP perovskites.However,recent reports of unusual dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2) have generated intense debate about its origin and remains controversial.Here,by combining continuous pressure tuning with in situ diagnostics,we have unambiguously revealed the underlying mechanisms that the 2D Cs_(2)Pb(SCN)_(2)Br_(2) exhibits an intrinsic blue emission at 2.66 eV and an absorption edge close to the emission peak.While the gradually formed CsPbBr3 is responsible for the green emission at 2.33 eV with the absorption shoulder at 2.41 eV.Furthermore,by fitting the temperature-dependent intensity of the intrinsic blue emission,we have determined the corrected value of exciton binding energy for 2D Cs_(2)Pb(SCN)_(2)Br_(2) to be 90 meV.Intriguingly,an emission enhancement of 2.5 times is achieved in Cs_(2)Pb(SCN)_(2)Br_(2) under a mild pressure within 0.8 GPa,caused by the pressuresuppressed exciton-phonon interaction.This work not only elucidates the origin of the dual emissions and two-edge absorption in Cs_(2)Pb(SCN)_(2)Br_(2),but it also provides a potential means to regulate and optimize the optoelectronic properties of 2D perovskites.
基金supported by the National Natural Science Foundation of China(No.92161105).
文摘Carbolong compounds as a metal-heteroaromatic compound with both organometallic properties andπ-conjugated systems exhibit great potential in organic catalysis and optoelectronic devices.In this work,for the first time,the“Bucket Effect”is revealed to promote the third-order nonlinear optical(NLO)performance in metal-heteroaromatic compounds.We have successfully constructed and investigated a series of novel metallapentalenes with higher third-order NLO performance benefited from the“Bucket Effect”.Meanwhile,aromaticity and electron−hole analysis further confirm the internal homogeneity of organometallic rings,reduced bandgap,and enhanced low-energy peak response resulted in the enhanced third-order NLO effects.The success of this work is discovering an emerging material library of high third-order NLO effects,and illustrating the feasibility of engineering the high response metal-heteroaromatic optical devices at the electronic structure level.
