An in-depth understanding of the photoconductivity and photocarrier density at the interface is of great significance for improving the performance of optoelectronic devices. However, extraction of the photoconductivi...An in-depth understanding of the photoconductivity and photocarrier density at the interface is of great significance for improving the performance of optoelectronic devices. However, extraction of the photoconductivity and photocarrier density at the heterojunction interface remains elusive. Herein, we have obtained the photoconductivity and photocarrier density of 173 nm Sb2Se3/Si(type-Ⅰ heterojunction) and 90 nm Sb2Se3/Si(type-Ⅱ heterojunction) utilizing terahertz(THz) time-domain spectroscopy(THz-TDS) and a theoretical Drude model. Since type-Ⅰ heterojunctions accelerate carrier recombination and type-Ⅱ heterojunctions accelerate carrier separation, the photoconductivity and photocarrier density of the type-Ⅱ heterojunction(21.8×10^(4)S·m^(-1),1.5 × 10^(15)cm^(-3)) are higher than those of the type-Ⅰ heterojunction(11.8×10^(4)S·m^(-1),0.8×10^(15)cm^(-3)). These results demonstrate that a type-Ⅱ heterojunction is superior to a type-Ⅰ heterojunction for THz wave modulation. This work highlights THz-TDS as an effective tool for studying photoconductivity and photocarrier density at the heterojunction interface. In turn, the intriguing interfacial photoconductivity effect provides a way to improve the THz wave modulation performance.展开更多
As a thin film solar cell absorber material, antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) has become a potential candidate recently because of its unique optical and electrical properties a...As a thin film solar cell absorber material, antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) has become a potential candidate recently because of its unique optical and electrical properties and easy fabrication method. X-ray photoelectron spectroscopy (XPS) was used to determine the stoichiometry and composition of electroless Sb<sub>2</sub>Se<sub>3</sub> thin films using depth profile studies. The surface layers were analyzed nearly stoichiometric. But the abundant amount of antimony makes the inner layer electrically more conductive.展开更多
In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostru...In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostructures including antimony selenide(Sb_2Se_3) nanowires and selenium(Se) microrods can be achieved by merely varying the volume ratio of ethylene glycol(EG) and H_2O free from expensive chemical and additional surfactant. The achieved uniform Sb_2Se_3 nanowire is single crystalline along [001]growth direction with a diameter of 100 nm and a length up to tens of micrometers. When evaluated as an anode of lithium-ion battery, Sb_2Se_3 nanowire can deliver a high reversible capacity of 650.2 m Ah g^(-1) at 100 mA g^(-1) and a capacity retention of 63.8% after long-term 1000 cycles at 1000 mA g^(-1), as well as superior rate capability(389.5 m Ah g^(-1) at 2000 mA g^(-1)). This easy solvent-mediated microwave synthesis approach exhibits its great universe and importance towards the fabrication of high-performance metal chalcogenide electrode materials for future low-cost, large-scale energy storage systems.展开更多
Antimony sulfide–selenide Sb2（S,Se）3,including Sb2S3and Sb2Se3,can be regarded as binary metal chalcogenides semiconductors since Sb2S3and Sb2Se3are isomorphous.They possess abundant elemental storage,nontoxicity,g...Antimony sulfide–selenide Sb2（S,Se）3,including Sb2S3and Sb2Se3,can be regarded as binary metal chalcogenides semiconductors since Sb2S3and Sb2Se3are isomorphous.They possess abundant elemental storage,nontoxicity,good stability with regard to moisture at elevated temperatures and suitable physical parameters for light absorption materials in solar cells.To date,quite a few attempts have been conducted in the materials synthesis,photovoltaic property investigation and device fabrication.Benefiting from previous investigation in thin film solar cells and new generation nanostructured solar cells,this class of materials has been applied in either sensitized-architecture or planar heterojunction solar cells.Decent power conversion efficiencies from 5%to 7.5%have been achieved.Apparently,further improvement on the efficiency is required for future practical applications.To give an overview of this research field,this paper displays some typical researches regarding the methodologies toward the antimony sulfide–selenide synthesis,development of interfacial materials and device fabrications,during which we highlight some critical findings that promote the efficiency enhancement.Finally,this paper proposes some outstanding issue regarding fundamental understanding of the materials,some viewpoints for the efficiency improvement and their future challenges in solar cell applications.展开更多
The photogenerated charge carrier separation and transportation of inside photocathodes can greatly influence the performance of photoelectrochemical(PEC)H2 production devices.Coupling TiO_(2) with p-type semiconducto...The photogenerated charge carrier separation and transportation of inside photocathodes can greatly influence the performance of photoelectrochemical(PEC)H2 production devices.Coupling TiO_(2) with p-type semiconductors to construct heterojunction structures is one of the most widely used strategies to facilitate charge separation and transportation.However,the band position of TiO_(2) could not perfectly match with all p-type semiconductors.Here,taking antimony selenide(Sb_(2)Se_(3))as an example,a rational strategy was developed by introducing a viologen electron transfer mediator(ETM)containing polymeric film(poly-1,1′-dially-[4,4′-bipyridine]-1,1′-diium,denoted as PV^(2+))at the interface between Sb_(2)Se_(3) and TiO_(2) to regulate the energy band alignment,which could inhibit the recombination of photogenerated charge carriers of interfaces.With Pt as a catalyst,the constructed Sb_(2)Se_(3)/PV^(2+)/TiO_(2)/Pt photocathode showed a superior PEC hydrogen generation activity with a photocurrent density of−18.6 mA cm^(-2) vs.a reversible hydrogen electrode(RHE)and a half-cell solar-to-hydrogen efficiency(HC-STH)of 1.54%at 0.17 V vs.RHE,which was much better than that of the related Sb_(2)Se_(3)/TiO_(2)/Pt photocathode without PV^(2+)(−9.8 mA cm^(-2),0.51%at 0.10 V vs.RHE).展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12261141662, 12074311, and 12004310)。
文摘An in-depth understanding of the photoconductivity and photocarrier density at the interface is of great significance for improving the performance of optoelectronic devices. However, extraction of the photoconductivity and photocarrier density at the heterojunction interface remains elusive. Herein, we have obtained the photoconductivity and photocarrier density of 173 nm Sb2Se3/Si(type-Ⅰ heterojunction) and 90 nm Sb2Se3/Si(type-Ⅱ heterojunction) utilizing terahertz(THz) time-domain spectroscopy(THz-TDS) and a theoretical Drude model. Since type-Ⅰ heterojunctions accelerate carrier recombination and type-Ⅱ heterojunctions accelerate carrier separation, the photoconductivity and photocarrier density of the type-Ⅱ heterojunction(21.8×10^(4)S·m^(-1),1.5 × 10^(15)cm^(-3)) are higher than those of the type-Ⅰ heterojunction(11.8×10^(4)S·m^(-1),0.8×10^(15)cm^(-3)). These results demonstrate that a type-Ⅱ heterojunction is superior to a type-Ⅰ heterojunction for THz wave modulation. This work highlights THz-TDS as an effective tool for studying photoconductivity and photocarrier density at the heterojunction interface. In turn, the intriguing interfacial photoconductivity effect provides a way to improve the THz wave modulation performance.
文摘As a thin film solar cell absorber material, antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) has become a potential candidate recently because of its unique optical and electrical properties and easy fabrication method. X-ray photoelectron spectroscopy (XPS) was used to determine the stoichiometry and composition of electroless Sb<sub>2</sub>Se<sub>3</sub> thin films using depth profile studies. The surface layers were analyzed nearly stoichiometric. But the abundant amount of antimony makes the inner layer electrically more conductive.
基金supported by the National Fund for Fostering Talents of Basic Science (J1103212)the Foundation for Outstanding Young Scientist in Shandong Province (BS2010CL036)~~
基金supported by the National Key Research and Development Program of China(2016YFA0202603)the National Basic Research Program of China(2013CB934103)+5 种基金the National Natural Science Foundation of China(51521001,51602239)the National Natural Science Fund for Distinguished Young Scholars(51425204)Yellow Crane Talent(Science&Technology)Program of Wuhan Citythe Fundamental Research Funds for the Central Universities(WUT:2016III001,2016III003,2016IVA090)the Programme of Introducing Talents of Discipline to Universities(B17034)support from the Lorraine Region(nowpart of Grand Est Region)Cooperation Research Lorraine/Hubei Program 2015/2017
文摘In this work, a fast(0.5 h), green microwave-assisted synthesis of single crystalline Sb_2Se_3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostructures including antimony selenide(Sb_2Se_3) nanowires and selenium(Se) microrods can be achieved by merely varying the volume ratio of ethylene glycol(EG) and H_2O free from expensive chemical and additional surfactant. The achieved uniform Sb_2Se_3 nanowire is single crystalline along [001]growth direction with a diameter of 100 nm and a length up to tens of micrometers. When evaluated as an anode of lithium-ion battery, Sb_2Se_3 nanowire can deliver a high reversible capacity of 650.2 m Ah g^(-1) at 100 mA g^(-1) and a capacity retention of 63.8% after long-term 1000 cycles at 1000 mA g^(-1), as well as superior rate capability(389.5 m Ah g^(-1) at 2000 mA g^(-1)). This easy solvent-mediated microwave synthesis approach exhibits its great universe and importance towards the fabrication of high-performance metal chalcogenide electrode materials for future low-cost, large-scale energy storage systems.
基金supported by the Recruitment Program of Global Expertsthe Fundamental Research Funds for the Central Universities(Nos.WK2060140022,WK2060140023 and WK2060140024)
文摘Antimony sulfide–selenide Sb2（S,Se）3,including Sb2S3and Sb2Se3,can be regarded as binary metal chalcogenides semiconductors since Sb2S3and Sb2Se3are isomorphous.They possess abundant elemental storage,nontoxicity,good stability with regard to moisture at elevated temperatures and suitable physical parameters for light absorption materials in solar cells.To date,quite a few attempts have been conducted in the materials synthesis,photovoltaic property investigation and device fabrication.Benefiting from previous investigation in thin film solar cells and new generation nanostructured solar cells,this class of materials has been applied in either sensitized-architecture or planar heterojunction solar cells.Decent power conversion efficiencies from 5%to 7.5%have been achieved.Apparently,further improvement on the efficiency is required for future practical applications.To give an overview of this research field,this paper displays some typical researches regarding the methodologies toward the antimony sulfide–selenide synthesis,development of interfacial materials and device fabrications,during which we highlight some critical findings that promote the efficiency enhancement.Finally,this paper proposes some outstanding issue regarding fundamental understanding of the materials,some viewpoints for the efficiency improvement and their future challenges in solar cell applications.
基金conducted by the Fundamental Research Center of Artificial Photosynthesis(FReCAP)financially supported by the National Natural Science Foundation of China(NSFC)(22172011 and 22088102)+2 种基金the K&A Wallenberg Foundation(KAW 2016.0072)Key Laboratory of Bio-based Chemicals of Liaoning Province of ChinaZhejiang Province Selected Funding for Postdoctoral Research Projects(ZJ2021001)for financial support.
文摘The photogenerated charge carrier separation and transportation of inside photocathodes can greatly influence the performance of photoelectrochemical(PEC)H2 production devices.Coupling TiO_(2) with p-type semiconductors to construct heterojunction structures is one of the most widely used strategies to facilitate charge separation and transportation.However,the band position of TiO_(2) could not perfectly match with all p-type semiconductors.Here,taking antimony selenide(Sb_(2)Se_(3))as an example,a rational strategy was developed by introducing a viologen electron transfer mediator(ETM)containing polymeric film(poly-1,1′-dially-[4,4′-bipyridine]-1,1′-diium,denoted as PV^(2+))at the interface between Sb_(2)Se_(3) and TiO_(2) to regulate the energy band alignment,which could inhibit the recombination of photogenerated charge carriers of interfaces.With Pt as a catalyst,the constructed Sb_(2)Se_(3)/PV^(2+)/TiO_(2)/Pt photocathode showed a superior PEC hydrogen generation activity with a photocurrent density of−18.6 mA cm^(-2) vs.a reversible hydrogen electrode(RHE)and a half-cell solar-to-hydrogen efficiency(HC-STH)of 1.54%at 0.17 V vs.RHE,which was much better than that of the related Sb_(2)Se_(3)/TiO_(2)/Pt photocathode without PV^(2+)(−9.8 mA cm^(-2),0.51%at 0.10 V vs.RHE).
