Two-dimensional transition metal dichalcogenides(2D TMDs)with metal-insulator transition(MIT)have garnered significant attention for their potential in elucidating electronic state regulation mechanisms and advancing ...Two-dimensional transition metal dichalcogenides(2D TMDs)with metal-insulator transition(MIT)have garnered significant attention for their potential in elucidating electronic state regulation mechanisms and advancing novel electronic devices,ultra-low power switches,and memory technologies.Generally,MIT behavior is often obscured by Schottky barrier(SB).Previous approaches,such as using four-probe methods or barrier-free van der Waals(vdW)semimetal electrodes,have aimed to eliminate the influence of SB on MIT.However,these methods are either complicated by intricate fabrication and testing processes or limited by the availability of suitable semimetal electrodes.Here,we demonstrated a bias voltage(Vds)-switchable MIT in pure vdW TMDs field-effect transistors(FETs)for the first time,driven by Vds-tunable effective SB and charge injection mechanisms.We identified a conversion voltage(V_(conversion)),which can be reduced by eliminating extra tunneling barriers introduced by vdW gaps before the inherent SB.This work offers comprehensive perspective on how tunneling barriers influence MIT and introduces a straightforward approach to fabricating MIT-based electronic devices.展开更多
The von Neumann architecture is encountering challenges,including the“memory wall”and“power wall”due to the separation of memory and central processing units,which imposes a major hurdle on today's massive dat...The von Neumann architecture is encountering challenges,including the“memory wall”and“power wall”due to the separation of memory and central processing units,which imposes a major hurdle on today's massive data processing.Neuromorphic computing,which combines data storage and spatiotemporal computation at the hardware level,represents a computing paradigm that surpasses the traditional von Neumann architecture.Artificial synapses are the basic building blocks of the artificial neural networks capable of neuromorphic computing,and require a high on/off ratio,high durability,low nonlinearity,and multiple conductance states.Recently,two-dimensional(2D)materials and their heterojunctions have emerged as a nanoscale hardware development platform for synaptic devices due to their intrinsic high surface-to-volume ratios and sensitivity to charge transfer at interfaces.Here,the latest progress of 2D material-based artificial synapses is reviewed regarding biomimetic principles,physical mechanisms,optimization methods,and application scenarios.In particular,there is a focus on how to improve resistive switching characteristics and synaptic plasticity of artificial synapses to meet actual needs.Finally,key technical challenges and future development paths for 2D material-based artificial neural networks are also explored.展开更多
n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction （SHJ） solar cells wh...n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction （SHJ） solar cells which was fabricated with different wafers in the top, middle and tail positions of the ingot, exhibited a stable high efficiency of〉 22% in spite of the various profiles of the resistivity and lifetime, which demonstrated the high material utilization of n-type ingot. In addition, for effectively converting the sunlight into electrical power, the pyramid size, pyramid density and roughness of surface of the Cz-Si wafer were investigated by scanning electron microscope （SEM） and transmission electron microscope （TEM）. Furthermore, the dependence of SHJ solar cell open- circuit voltage on the surface topography was discussed, which indicated that the uniformity of surface pyramid helps to improve the open-circuit voltage and conversion efficiency. Moreover, the simulation revealed that the highest efficiency of the SHJ solar cell could be achieved by the wafer with a thickness of 100 μm. Fortunately, over 23% of the conversion efficiency of the SHJ solar cell with a wafer thickness of 100 μm was obtained based on the systematic optimization of cell fabrication process in the pilot production line. Evidently, the large availability of both n-type ingot and thinner wafer strongly supported the lower cost fabrication of high efficiency SHJ solar cell.展开更多
Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still ...Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still largely constrained by the widebandgap perovskite solar cells which show considerable open-circuit voltage(VOC)losses.Here,we increase the VOCand PCE of wide-bandgap perovskite solar cells by changing the hole transport layer(HTL)from commonly used poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)(PTAA)to in-situ cross-linked small molecule N_(4),N_(4)′-di(naphthalen-1-yl)-N_(4),N_(4)′-bis(4-vinylphenyl)biphenyl-4,4′-diamine(VNPB).The stronger interaction and lower trap density at the VNPB/perovskite interface improve the PCE and stability of wide-bandgap perovskite solar cells.By using the cross-linked HTL for front wide-bandgap subcells,PCEs of 24.9%and 25.4%have been achieved in perovskite/perovskite and perovskite/silicon tandem solar cells,respectively.The results demonstrate that cross-linkable small molecules are promising for high-efficiency and cost-effective perovskite tandem photovoltaic devices.展开更多
With the gradual progression of the carbon neutrality target,the future of our electricity supply will experience a massive increase in solar generation,and approximately 50%of the global electricity generation will c...With the gradual progression of the carbon neutrality target,the future of our electricity supply will experience a massive increase in solar generation,and approximately 50%of the global electricity generation will come from solar generation by 2050.This provides the opportunity for researchers to diversify the applications of photovoltaics(PVs)and integrate for daily use in the future.Flexible solar cell technology is the next frontier in solar PV and is the key way to achieve CO_(2)neutrality.The integration of PV technology with other fields will greatly broaden the development areas for the PV industry,providing products with higher added value.In this paper,we reviewed the latest research progress on flexible solar cells(perovskite solar cells,organic solar cells,and flexible silicon solar cells),and proposed the future applications of flexible solar cell technology.展开更多
Hydrogenated amorphous silicon(a-Si:H)has a long history in the development of photovoltaics,especially in the research field of a-Si:H thin-film solar cells and crystalline/amorphous silicon heterojunction solar cell...Hydrogenated amorphous silicon(a-Si:H)has a long history in the development of photovoltaics,especially in the research field of a-Si:H thin-film solar cells and crystalline/amorphous silicon heterojunction solar cells.More than 40 years ago,Staebler and Wronski reported conductance decrease of a-Si:H induced by light soaking.This phenomenon has been widely investigated for electronic applications.In contrast to that,we found light soaking can also improve dark conductance of a-Si:H when boron or phosphorus atoms are doped into the amorphous network.Here we survey these two photoelectronic effects,and discuss their implementations to silicon solar cells.展开更多
基金supported by the open research of Songshan Lake Materials Laboratory(No.2023SLABFK07)the National Science Foundation of China(Nos.62304151,62204170,and 62474124)+2 种基金the Natural Science Foundation of Tianjin(No.24JCQNJC00520)the China Postdoctoral Science Foundation(No.2023M742585)the State Key Laboratory of Fluid Power and Mechatronic Systems under Grant(No.GZKF-202327).
文摘Two-dimensional transition metal dichalcogenides(2D TMDs)with metal-insulator transition(MIT)have garnered significant attention for their potential in elucidating electronic state regulation mechanisms and advancing novel electronic devices,ultra-low power switches,and memory technologies.Generally,MIT behavior is often obscured by Schottky barrier(SB).Previous approaches,such as using four-probe methods or barrier-free van der Waals(vdW)semimetal electrodes,have aimed to eliminate the influence of SB on MIT.However,these methods are either complicated by intricate fabrication and testing processes or limited by the availability of suitable semimetal electrodes.Here,we demonstrated a bias voltage(Vds)-switchable MIT in pure vdW TMDs field-effect transistors(FETs)for the first time,driven by Vds-tunable effective SB and charge injection mechanisms.We identified a conversion voltage(V_(conversion)),which can be reduced by eliminating extra tunneling barriers introduced by vdW gaps before the inherent SB.This work offers comprehensive perspective on how tunneling barriers influence MIT and introduces a straightforward approach to fabricating MIT-based electronic devices.
基金supported by the Open Research of Songshan Lake Materials Laboratory(2023SLABFK07)the National Natural Science Foundation of China(62304151,62204170 and 62474124)+2 种基金the China Postdoctoral Science Foundation(2023M742585)the Natural Science Foundation of Tianjin(24JCQNJC00520)the State Key Laboratory of Fluid Power and Mechatronic Systems(GZKF-202327).
文摘The von Neumann architecture is encountering challenges,including the“memory wall”and“power wall”due to the separation of memory and central processing units,which imposes a major hurdle on today's massive data processing.Neuromorphic computing,which combines data storage and spatiotemporal computation at the hardware level,represents a computing paradigm that surpasses the traditional von Neumann architecture.Artificial synapses are the basic building blocks of the artificial neural networks capable of neuromorphic computing,and require a high on/off ratio,high durability,low nonlinearity,and multiple conductance states.Recently,two-dimensional(2D)materials and their heterojunctions have emerged as a nanoscale hardware development platform for synaptic devices due to their intrinsic high surface-to-volume ratios and sensitivity to charge transfer at interfaces.Here,the latest progress of 2D material-based artificial synapses is reviewed regarding biomimetic principles,physical mechanisms,optimization methods,and application scenarios.In particular,there is a focus on how to improve resistive switching characteristics and synaptic plasticity of artificial synapses to meet actual needs.Finally,key technical challenges and future development paths for 2D material-based artificial neural networks are also explored.
文摘n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction （SHJ） solar cells which was fabricated with different wafers in the top, middle and tail positions of the ingot, exhibited a stable high efficiency of〉 22% in spite of the various profiles of the resistivity and lifetime, which demonstrated the high material utilization of n-type ingot. In addition, for effectively converting the sunlight into electrical power, the pyramid size, pyramid density and roughness of surface of the Cz-Si wafer were investigated by scanning electron microscope （SEM） and transmission electron microscope （TEM）. Furthermore, the dependence of SHJ solar cell open- circuit voltage on the surface topography was discussed, which indicated that the uniformity of surface pyramid helps to improve the open-circuit voltage and conversion efficiency. Moreover, the simulation revealed that the highest efficiency of the SHJ solar cell could be achieved by the wafer with a thickness of 100 μm. Fortunately, over 23% of the conversion efficiency of the SHJ solar cell with a wafer thickness of 100 μm was obtained based on the systematic optimization of cell fabrication process in the pilot production line. Evidently, the large availability of both n-type ingot and thinner wafer strongly supported the lower cost fabrication of high efficiency SHJ solar cell.
基金financially supported by the National Key R&D Program of China(2018YFB1500102)the National Natural Science Foundation of China(61974063,22005139)+5 种基金Natural Science Foundation of Jiangsu Province(BK20202008,BK20190315)Fundamental Research Funds for the Central Universities(0205/14380252)Program for Innovative Talents and Entrepreneur in Jiangsusupported by the National Natural Science Foundation of China(62074153)Strategic Priority Research Program of Chinese Academy of Sciences(XDA17020403)Science and Technology Commission of Shanghai(19DZ1207602 and 20DZ1207103)。
文摘Perovskite tandem solar cells have recently received extensive attention due to their promise of achieving power conversion efficiency(PCE)beyond the limits of single-junction cells.However,their performance is still largely constrained by the widebandgap perovskite solar cells which show considerable open-circuit voltage(VOC)losses.Here,we increase the VOCand PCE of wide-bandgap perovskite solar cells by changing the hole transport layer(HTL)from commonly used poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)(PTAA)to in-situ cross-linked small molecule N_(4),N_(4)′-di(naphthalen-1-yl)-N_(4),N_(4)′-bis(4-vinylphenyl)biphenyl-4,4′-diamine(VNPB).The stronger interaction and lower trap density at the VNPB/perovskite interface improve the PCE and stability of wide-bandgap perovskite solar cells.By using the cross-linked HTL for front wide-bandgap subcells,PCEs of 24.9%and 25.4%have been achieved in perovskite/perovskite and perovskite/silicon tandem solar cells,respectively.The results demonstrate that cross-linkable small molecules are promising for high-efficiency and cost-effective perovskite tandem photovoltaic devices.
基金supported by the National Natural Science Foundation of China(T2322028,62004208,and 62074153)the Science and Technology Commission of Shanghai Municipality(22ZR1473200)+1 种基金China National Key R&D Program(2022YFC2807104)the Research on the Key Technologies of High Efficiency Ultra-thin Heterojunction Solar Cell and Module(HNKJ22-H154).
基金supported by the National Natural Science Foundation of China(T2322028,62105129,and 62004208)Sichuan Science and Technology Program(2023ZYD0163)+2 种基金the Science and Technology Commission of Shanghai Municipality(22ZR1473200)the Rising-Star Program of the Shanghai 2023 Science and Technology Innovation Action Plan(23QA1411100)the Autonomous Deployment Project of State Key Laboratory of Materials for Integrated Circuits(NKLJC-Z2023ZD01)。
文摘With the gradual progression of the carbon neutrality target,the future of our electricity supply will experience a massive increase in solar generation,and approximately 50%of the global electricity generation will come from solar generation by 2050.This provides the opportunity for researchers to diversify the applications of photovoltaics(PVs)and integrate for daily use in the future.Flexible solar cell technology is the next frontier in solar PV and is the key way to achieve CO_(2)neutrality.The integration of PV technology with other fields will greatly broaden the development areas for the PV industry,providing products with higher added value.In this paper,we reviewed the latest research progress on flexible solar cells(perovskite solar cells,organic solar cells,and flexible silicon solar cells),and proposed the future applications of flexible solar cell technology.
基金supports from National Natural Science Foundations of China(Nos.T2322028,62004208,62074153)Science and Technology Commission of Shanghai Municipality(No.22ZR1473200)+1 种基金Talent plan of Shanghai Branch,Chinese Academy of Sciences(No.CASSHB-QNPD-2023-001)Shanghai Rising-Star Program(No.23QA1411100).
文摘Hydrogenated amorphous silicon(a-Si:H)has a long history in the development of photovoltaics,especially in the research field of a-Si:H thin-film solar cells and crystalline/amorphous silicon heterojunction solar cells.More than 40 years ago,Staebler and Wronski reported conductance decrease of a-Si:H induced by light soaking.This phenomenon has been widely investigated for electronic applications.In contrast to that,we found light soaking can also improve dark conductance of a-Si:H when boron or phosphorus atoms are doped into the amorphous network.Here we survey these two photoelectronic effects,and discuss their implementations to silicon solar cells.
