Two-dimensional （2D） layered transition metal dichalcogenide （TMD） materials （e.g., MoS2） have attracted considerable interest due to their atomically thin geometry and semiconducting electronic properties. With...Two-dimensional （2D） layered transition metal dichalcogenide （TMD） materials （e.g., MoS2） have attracted considerable interest due to their atomically thin geometry and semiconducting electronic properties. With ultrahigh surface to volume ratio, the electronic properties of these atomically thin semiconductors can be readily modulated by their environment. Here we report an investigation of the effects of mercury（II） （Hg^2＋） ions on the electrical transport properties of few-layer molybdenum disulfide （MoS2）. The interaction between Hg^2＋ ions and few-layer MoS2 was studied by field-effect transistor measurements and photoluminescence. Due to a high binding affinity between Hg2. ions and the sulfur sites on the surface of MoS2 layers, Hg^2＋ ions can strongly bind to MoS2. We show that the binding of Hg^2＋ can produce a p-type doping effect to reduce the electron concentration in n-type few-layer MoS2. It can thus effectively modulate the electron transport and photoluminescence properties in few-layer MoS2. By monitoring the conductance change of few-layer MoS2 in varying concentration Hg2~ solutions, we further show that few-layer MoS2 transistors can function as highly sensitive sensors for rapid electrical detection of Hg^2＋ ion with a detection limit of 30 pM.展开更多
Due to distinctive lattice and electronic properties,the thiocyanate anion(SCN-)perovskite as an alluring two-dimensional(2D)material system,can be applied in optoelectronic devices.Herein,both photovoltaic and photod...Due to distinctive lattice and electronic properties,the thiocyanate anion(SCN-)perovskite as an alluring two-dimensional(2D)material system,can be applied in optoelectronic devices.Herein,both photovoltaic and photodetection performances of the 2D Cs2Pb(SCN)2I2 have been investigated.Compared with the conventional cationic 2D perovskites,Cs2Pb(SCN)2I2 possesses ultra-small interlayer spacing,additional interlayer nano channels,which is thus beneficial for charge transport ability.The planar heterojunction solar cell based on Cs2Pb(SCN)2I2 as the light absorber,has presented the highest power conversion efficiency among long-chain-cation-based 2D perovskite devices.Besides,the Cs2Pb(SCN)2I2-based photodetector also exhibits much higher photodetection performance(i.e.quantum efficiency,on/off ratio,responsivity,detectivity,response speed,polarization sensitivity and detection stability).It is thus suggested that these outstanding photoelectric characteristics of Cs2Pb(SCN)2I2 could bring huge opportunities for its more abundant optoelectronic applications,such as field-effect transistor and light-emitting diodes.展开更多
Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic p...Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic performance in organic solar cells(OSCs).Herein,we demonstrated a solvent-water evaporation(SWE)strategy,which can effectively remove the water-induced traps that are omnipresent in photoactive layers,leading to a significant improvement in device performance.A higher power conversion efficiency of 17.10%and a better device photostability are achieved by using this SWE method,as compared with the untreated binary PM6:Y6 system(15.83%).We highlight the water-related traps as a limiting factor for carrier transport and extraction properties,and further reveal the good universality of the SWE strategy applied into OSCs.In addition,organic light-emitting diodes and organic field-effect transistors are investigated to demonstrate the applicability of this SWE approach.This strategy presents a major step forward for advancing the field of organic electronics.展开更多
文摘Two-dimensional （2D） layered transition metal dichalcogenide （TMD） materials （e.g., MoS2） have attracted considerable interest due to their atomically thin geometry and semiconducting electronic properties. With ultrahigh surface to volume ratio, the electronic properties of these atomically thin semiconductors can be readily modulated by their environment. Here we report an investigation of the effects of mercury（II） （Hg^2＋） ions on the electrical transport properties of few-layer molybdenum disulfide （MoS2）. The interaction between Hg^2＋ ions and few-layer MoS2 was studied by field-effect transistor measurements and photoluminescence. Due to a high binding affinity between Hg2. ions and the sulfur sites on the surface of MoS2 layers, Hg^2＋ ions can strongly bind to MoS2. We show that the binding of Hg^2＋ can produce a p-type doping effect to reduce the electron concentration in n-type few-layer MoS2. It can thus effectively modulate the electron transport and photoluminescence properties in few-layer MoS2. By monitoring the conductance change of few-layer MoS2 in varying concentration Hg2~ solutions, we further show that few-layer MoS2 transistors can function as highly sensitive sensors for rapid electrical detection of Hg^2＋ ion with a detection limit of 30 pM.
基金supported by the National Key R&D Program of China(2018YFB1500101)the National Natural Science Foundation of China(11874402,51421002,51627803,91733301 and 51761145042)the International Partnership Program of Chinese Academy of Sciences(112111KYSB20170089)。
文摘Due to distinctive lattice and electronic properties,the thiocyanate anion(SCN-)perovskite as an alluring two-dimensional(2D)material system,can be applied in optoelectronic devices.Herein,both photovoltaic and photodetection performances of the 2D Cs2Pb(SCN)2I2 have been investigated.Compared with the conventional cationic 2D perovskites,Cs2Pb(SCN)2I2 possesses ultra-small interlayer spacing,additional interlayer nano channels,which is thus beneficial for charge transport ability.The planar heterojunction solar cell based on Cs2Pb(SCN)2I2 as the light absorber,has presented the highest power conversion efficiency among long-chain-cation-based 2D perovskite devices.Besides,the Cs2Pb(SCN)2I2-based photodetector also exhibits much higher photodetection performance(i.e.quantum efficiency,on/off ratio,responsivity,detectivity,response speed,polarization sensitivity and detection stability).It is thus suggested that these outstanding photoelectric characteristics of Cs2Pb(SCN)2I2 could bring huge opportunities for its more abundant optoelectronic applications,such as field-effect transistor and light-emitting diodes.
基金the National Natural Science Foundation of China(NSFC)(51773157 and 52061135206)the Fundamental Research Funds for the Central UniversitiesThe authors also thank the support of the opening project of Key Laboratory of Materials Processing and Mold and Beijing National Laboratory for Molecular Sciences(BNLMS201905).
文摘Clusters of water molecules have low ionization energies because of stabilization of charge from the dipole moment of surrounding molecules,and thus can form potential traps resulting in the undesirable photovoltaic performance in organic solar cells(OSCs).Herein,we demonstrated a solvent-water evaporation(SWE)strategy,which can effectively remove the water-induced traps that are omnipresent in photoactive layers,leading to a significant improvement in device performance.A higher power conversion efficiency of 17.10%and a better device photostability are achieved by using this SWE method,as compared with the untreated binary PM6:Y6 system(15.83%).We highlight the water-related traps as a limiting factor for carrier transport and extraction properties,and further reveal the good universality of the SWE strategy applied into OSCs.In addition,organic light-emitting diodes and organic field-effect transistors are investigated to demonstrate the applicability of this SWE approach.This strategy presents a major step forward for advancing the field of organic electronics.
