Perovskite-organic tandem solar cells(TSCs)have emerged as a groundbreaking technology in the realm of photovoltaics,showcasing remarkable enhancements in efficiency and significant potential for practical application...Perovskite-organic tandem solar cells(TSCs)have emerged as a groundbreaking technology in the realm of photovoltaics,showcasing remarkable enhancements in efficiency and significant potential for practical applications.Perovskite-organic TSCs also exhibit facile fabrication surpassing that of all-perovskite or all-organic TSCs,attributing to the advantageous utilization of orthogonal solvents enabling sequential solution process for each subcell.The perovskite-organic TSCs capitalize on the complementary light absorption characteristics of perovskite and organic materials.There is a promising prospect of achieving further enhanced power conversion efficiencies by covering a broad range of the solar spectrum with optimized perovskite absorber,organic semiconductors as well as the interconnecting layer's optical and electrical properties.This review comprehensively analyzes the recent advancements in perovskite-organic TSCs,highlighting the synergistic effects of combining perovskite with a low open-circuit voltage deficit,organic materials with broader light absorption,and interconnecting layers with reduced optical and electrical loss.Meanwhile,the underlying device architecture design,regulation strategies,and key challenges facing the high performance of the perovskite-organic TSCs are also discussed.展开更多
Narrow-bandgap materials possess the intriguing optical-electric properties and unique structures,which can be widely applied in the field of photonics,energy optoelectronic sensing and biomedicine,etc.Nowadays,the re...Narrow-bandgap materials possess the intriguing optical-electric properties and unique structures,which can be widely applied in the field of photonics,energy optoelectronic sensing and biomedicine,etc.Nowadays,the researches on nonlinear optical properties of narrow-bandgap materials have attracted extensive attention worldwide.In this paper,we review the progress of narrow-bandgap materials from many aspects,such as background,nonlinear optical properties,energy band structure,methods of preparation,and applications.These materials have obvious nonlinear optical characteristics and the interaction with the short pulse laser excitation shows the extremely strong nonlinear absorption characteristics,which leads to the optical limiting or saturable absorption related to Pauli blocking and excited state absorption.Especially,some of these novel narrow-bandgap materials have been utilized for the generation of ultrashort pulse that covers the range from the visible to mid-infrared wavelength regions.Hence,the study on these materials paves a new way for the advancement of optoelctronics devices.展开更多
Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells(all-PSCs).Herein,we developed a novel polymer acceptor PNT withπ-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]nap...Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells(all-PSCs).Herein,we developed a novel polymer acceptor PNT withπ-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile(CPNM)end groups.Compared to commonly used 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1ylidene)malononitrile(IC)units,CPNM units have a further extended fused ring,providing the PNT polymer with extended absorption into the near-IR region(903 nm)and exhibiting a narrow optical bandgap(1.37 eV).Furthermore,PNT exhibits a high electron mobility(6.79×10^(−4) cm^(2)·V^(−1)·S^(−1))and a relatively high-lying lowest unoccupied molecular orbital(LUMO)energy level of−3.80 eV.When blended with PBDB-T,all-PSC achieves a power conversion efficiency(PCE)of 13.7%and a high short-circuit current density(JSC)of 24.4 mA·cm^(−2),mainly attributed to broad absorption(600—900 nm)and efficient charge separation and collection.Our study provides a promising polymer acceptor for all-PSCs and demonstrates thatπ-extended CPNM units are important to achieve high-performance for all-PSCs.展开更多
Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of tr...Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of triple cations in mixed Sn–Pb iodides is studied by performing a wide range of compositional screenings over mechanochemically synthesized bulk and solution-processed thin films.A ternary phase map of FA(Sn_(0.6)Pb_(0.4))I_(3),MA(Sn_(0.6)Pb_(0.4))I_(3),and Cs(Sn_(0.6)Pb_(0.4))I_(3)is formed,and a promising composition window of(FA_(0.6-x)MA_(0.4)Cs_(x))Sn_(0.6)Pb_(0.4)I_(3)(0≤x≤0.1)is demonstrated through phase,photoluminescence,and stability evaluations.Solar cell performance and chemical stability across the targeted compositional space are investigated,and FA_(0.55)MA_(0.4)Cs_(0.05)Sn_(0.6)Pb_(0.4)I_(3)with strain-relaxed lattices,reduced defect densities,and improved oxidation stability is demonstrated.The inverted perovskite solar cells with the optimal composition demonstrate a power conversion efficiency of over 22%with an open-circuit voltage of 0.867 V,which corresponds to voltage loss of 0.363 V,promising for the development of narrow-bandgap perovskite solar cells.展开更多
Carbon nanotube field-effect transistor(CNT FET)has been considered as a promising candidate for future high-performance and low-power integrated circuits(ICs)applications owing to its ballistic transport and excellen...Carbon nanotube field-effect transistor(CNT FET)has been considered as a promising candidate for future high-performance and low-power integrated circuits(ICs)applications owing to its ballistic transport and excellent immunity to short channel effects(SCEs).Still,it easily suffers from the ambipolar property,and severe leakage current at off-state originated from gate-induced drain leakage(GIDL)in CNT FETs with small bandgap.Although some modifications on device structure have been experimentally demonstrated to suppress the leakage current in CNT FETs,there is still a lack of the structure with excellent scalability,which will hamper the development of CNT FETs toward a competitive technology node.Here,we explore how the device geometry design affects the leakage current in CNT FETs,and then propose the possible device structures to suppress off-state current and check their availability through the two-dimensional(2D)TCAD simulations.Among all the proposed structures,the L-shaped-spacer CNT FET exhibits significantly suppressed leakage current and excellent scalability down to sub-50 nm with a simple self-aligned gate process.According to the simulation results,the 50 nm gate-length L-shaped-spacer CNT FET exhibits an off-state current as low as approximately 1 nA/μm and an on-current as high as about 2.1 mA/μm at a supply voltage of-1 V and then can be extended as a universal device structure to suppress leakage current for all the narrow-bandgap semiconductors based FETs.展开更多
Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize t...Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize the photoelectric properties is reported.A new narrow bandgap(1.30 eV)chlorinated non-fullerene electron acceptor(Y15),based on benzo[d][1,2,3] triazole with two 3-undecylthieno[2’,3’:4,5] thieno[3,2-b] pyrrole fused-7-heterocyclic ring,with absorption edge extending to the near-infrared(NIR) region,namely A-DA’D-A type structure,is designed and synthesized.Its electrochemical and optoelectronic properties are systematically investigated.Benefitting from its NIR light harvesting,the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency(PCE) of 14.13%,when blending with a wide bandgap polymer donor PM6.Our results show that the A-DA’D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells(PSCs).展开更多
To achieve the red-shifted absorptions and appropriate energy levels of A-D-A type non-fullerene acceptors(NFAs), in this work, we design and synthesize two new NFAs, named TPDCIC and TPDCNC, whose electron-donating(D...To achieve the red-shifted absorptions and appropriate energy levels of A-D-A type non-fullerene acceptors(NFAs), in this work, we design and synthesize two new NFAs, named TPDCIC and TPDCNC, whose electron-donating(D) unit is constructed by a thieno[3,4-c]pyrrole-4,6-dione(TPD) core attached to two cyclopentadithiophene(CPDT) moieties at both sides, and the electronaccepting(A) end-groups are 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC) and 2-(3-oxo-2,3-dihydro-1 H-cyclopenta[b]naphthalen-1-ylidene)malononitrile(NC), respectively. Benefiting from TPD core, which easily forms quinoid structure and O···H or O···S intramolecular noncovalent interactions, TPDCIC and TPDCNC show more delocalization of π-electrons and perfect planar molecular geometries, giving the absorption ranges extended to 822 and 852 nm, respectively. Furthermore, the highest occupied molecular orbital(HOMO) levels of TPDCIC and TPDCNC remain relatively low-lying due to the electronegativity of the carbonyl groups on TPD core. Considering that the absorptions and energy levels of the two NFAs match well with those of a widely used polymer donor, PBDB-T, we fabricate two kinds of organic solar cells(OSCs) based on the PBDB-T:TPDCIC and PBDB-T:TPDCNC blended films, respectively. Through a series of optimizations, the TPDCIC-based devices yield an impressing power conversion efficiency(PCE)of 10.12% with a large short-circuit current density(JSC) of 18.16 mA·cm-2, and the TPDCNC-based ones exhibit a comparable PCE of9.80% with a JSC of 17.40 mA·cm-2. Our work is the first report of the TPD-core-based A-D-A type NFAs, providing a good reference for the molecular design of high-performance NFAs.展开更多
基金Guangdong Grants,Grant/Award Numbers:2021QN02L138,2021ZT09C064Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20220530115013029,ZDSYS20220527171403009+1 种基金National Natural Science Foundation of China,Grant/Award Number:22109067Guangdong Provincial Science and Technology Program,Grant/Award Number:2022A1515010085。
文摘Perovskite-organic tandem solar cells(TSCs)have emerged as a groundbreaking technology in the realm of photovoltaics,showcasing remarkable enhancements in efficiency and significant potential for practical applications.Perovskite-organic TSCs also exhibit facile fabrication surpassing that of all-perovskite or all-organic TSCs,attributing to the advantageous utilization of orthogonal solvents enabling sequential solution process for each subcell.The perovskite-organic TSCs capitalize on the complementary light absorption characteristics of perovskite and organic materials.There is a promising prospect of achieving further enhanced power conversion efficiencies by covering a broad range of the solar spectrum with optimized perovskite absorber,organic semiconductors as well as the interconnecting layer's optical and electrical properties.This review comprehensively analyzes the recent advancements in perovskite-organic TSCs,highlighting the synergistic effects of combining perovskite with a low open-circuit voltage deficit,organic materials with broader light absorption,and interconnecting layers with reduced optical and electrical loss.Meanwhile,the underlying device architecture design,regulation strategies,and key challenges facing the high performance of the perovskite-organic TSCs are also discussed.
基金This research was supported by the National Natural Science Foundation of China(Grant Nos.61605106,61875138,61435010,and 6181101252)the International Science&Technology Cooperation and Exchanges Project of Shaanxi(No.2020KW-005)+3 种基金Funded projects for the Academic Leader and Academic Backbones,Shaanxi Normal University(No.18QNGG006)Starting Grants of Shaanxi Normal University(Grant Nos.1112010209 and 1110010717)Fundamental Research Funds For the Central Universities(No.GK201802006)the Open Research Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(No.SKLST201809).
文摘Narrow-bandgap materials possess the intriguing optical-electric properties and unique structures,which can be widely applied in the field of photonics,energy optoelectronic sensing and biomedicine,etc.Nowadays,the researches on nonlinear optical properties of narrow-bandgap materials have attracted extensive attention worldwide.In this paper,we review the progress of narrow-bandgap materials from many aspects,such as background,nonlinear optical properties,energy band structure,methods of preparation,and applications.These materials have obvious nonlinear optical characteristics and the interaction with the short pulse laser excitation shows the extremely strong nonlinear absorption characteristics,which leads to the optical limiting or saturable absorption related to Pauli blocking and excited state absorption.Especially,some of these novel narrow-bandgap materials have been utilized for the generation of ultrashort pulse that covers the range from the visible to mid-infrared wavelength regions.Hence,the study on these materials paves a new way for the advancement of optoelctronics devices.
基金supported by National Natural Science Foundation of China(NSFC)(No.51973146)Shandong Provincial Natural Science Foundation(ZR2022JQ09)。
文摘Narrow-bandgap n-type polymers are essential for advancing the development of all-polymer solar cells(all-PSCs).Herein,we developed a novel polymer acceptor PNT withπ-extended 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile(CPNM)end groups.Compared to commonly used 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1ylidene)malononitrile(IC)units,CPNM units have a further extended fused ring,providing the PNT polymer with extended absorption into the near-IR region(903 nm)and exhibiting a narrow optical bandgap(1.37 eV).Furthermore,PNT exhibits a high electron mobility(6.79×10^(−4) cm^(2)·V^(−1)·S^(−1))and a relatively high-lying lowest unoccupied molecular orbital(LUMO)energy level of−3.80 eV.When blended with PBDB-T,all-PSC achieves a power conversion efficiency(PCE)of 13.7%and a high short-circuit current density(JSC)of 24.4 mA·cm^(−2),mainly attributed to broad absorption(600—900 nm)and efficient charge separation and collection.Our study provides a promising polymer acceptor for all-PSCs and demonstrates thatπ-extended CPNM units are important to achieve high-performance for all-PSCs.
基金supported by the Korea Electric Power Corporation(Grant number:R20XO02-1)the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT(NRF-2019R1A2C1084010).
文摘Mixed tin-ead perovskites suffer from structural instability and rapid tin oxidation;thus,the investigation of their optimal composition ranges is important to address these inherent weaknesses.The critical role of triple cations in mixed Sn–Pb iodides is studied by performing a wide range of compositional screenings over mechanochemically synthesized bulk and solution-processed thin films.A ternary phase map of FA(Sn_(0.6)Pb_(0.4))I_(3),MA(Sn_(0.6)Pb_(0.4))I_(3),and Cs(Sn_(0.6)Pb_(0.4))I_(3)is formed,and a promising composition window of(FA_(0.6-x)MA_(0.4)Cs_(x))Sn_(0.6)Pb_(0.4)I_(3)(0≤x≤0.1)is demonstrated through phase,photoluminescence,and stability evaluations.Solar cell performance and chemical stability across the targeted compositional space are investigated,and FA_(0.55)MA_(0.4)Cs_(0.05)Sn_(0.6)Pb_(0.4)I_(3)with strain-relaxed lattices,reduced defect densities,and improved oxidation stability is demonstrated.The inverted perovskite solar cells with the optimal composition demonstrate a power conversion efficiency of over 22%with an open-circuit voltage of 0.867 V,which corresponds to voltage loss of 0.363 V,promising for the development of narrow-bandgap perovskite solar cells.
基金the National Key Research&Development Program(No.2016YFA0201901)the National Natural Science Foundation of China(No.61888102)the Beijing Municipal Science and Technology Commission(No.D1711000066170021-2).
文摘Carbon nanotube field-effect transistor(CNT FET)has been considered as a promising candidate for future high-performance and low-power integrated circuits(ICs)applications owing to its ballistic transport and excellent immunity to short channel effects(SCEs).Still,it easily suffers from the ambipolar property,and severe leakage current at off-state originated from gate-induced drain leakage(GIDL)in CNT FETs with small bandgap.Although some modifications on device structure have been experimentally demonstrated to suppress the leakage current in CNT FETs,there is still a lack of the structure with excellent scalability,which will hamper the development of CNT FETs toward a competitive technology node.Here,we explore how the device geometry design affects the leakage current in CNT FETs,and then propose the possible device structures to suppress off-state current and check their availability through the two-dimensional(2D)TCAD simulations.Among all the proposed structures,the L-shaped-spacer CNT FET exhibits significantly suppressed leakage current and excellent scalability down to sub-50 nm with a simple self-aligned gate process.According to the simulation results,the 50 nm gate-length L-shaped-spacer CNT FET exhibits an off-state current as low as approximately 1 nA/μm and an on-current as high as about 2.1 mA/μm at a supply voltage of-1 V and then can be extended as a universal device structure to suppress leakage current for all the narrow-bandgap semiconductors based FETs.
文摘利用基于萘[1,2-c:5,6-c]二[1,2,5]噻二唑共轭聚合物(NTOD)为给体,富勒烯衍生物PC71BM为受体,制备本体异质结聚合物光探测器.NTOD与PC71BM的共混薄膜吸收范围为300~830 nm.通过对NTOD:PC71BM活性层厚度的调控实现器件暗电流密度的显著降低,增强了探测器的二极管性能,同时保持较高的外量子转化效率.当活性层厚度为385 nm时,聚合物光探测器在-0.1 V偏压下的暗电流为6.69×10–10A cm^(-2).在–0.1 V偏压下器件在440~800 nm的工作波段的比探测率均超过1013 cm Hz^(1/2)W^(-1),处于750 nm的工作波长下达到最大比探测率为1.50×1013 cm Hz^(1/2) W^(-1),光响应率为0.22 A W^(-1),这些结果表明基于NTOD:PC71BM的有机光探测器具有广阔的应用前景.
基金financially supported by the National Natural Science Foundation of China (Nos.51811530096, 21875286)the National Key Research & Development Projects of China (No.2017YFA0206600)Science Fund for Distinguished Young Scholars of Hunan Province (No.2017JJ1029)
文摘Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future.Here,the strategy that uses chemical structure modification to optimize the photoelectric properties is reported.A new narrow bandgap(1.30 eV)chlorinated non-fullerene electron acceptor(Y15),based on benzo[d][1,2,3] triazole with two 3-undecylthieno[2’,3’:4,5] thieno[3,2-b] pyrrole fused-7-heterocyclic ring,with absorption edge extending to the near-infrared(NIR) region,namely A-DA’D-A type structure,is designed and synthesized.Its electrochemical and optoelectronic properties are systematically investigated.Benefitting from its NIR light harvesting,the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency(PCE) of 14.13%,when blending with a wide bandgap polymer donor PM6.Our results show that the A-DA’D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells(PSCs).
基金financially supported by the National Natural Science Foundation of China (Nos. 21875216, 21734008)Zhejiang Province Science and Technology Plan (No. 2018C01047)the financial support from Research Grant Council of Hong Kong (General Research Fund No. 14314216, CUHK Direct Grant No. 4053227)
文摘To achieve the red-shifted absorptions and appropriate energy levels of A-D-A type non-fullerene acceptors(NFAs), in this work, we design and synthesize two new NFAs, named TPDCIC and TPDCNC, whose electron-donating(D) unit is constructed by a thieno[3,4-c]pyrrole-4,6-dione(TPD) core attached to two cyclopentadithiophene(CPDT) moieties at both sides, and the electronaccepting(A) end-groups are 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile(IC) and 2-(3-oxo-2,3-dihydro-1 H-cyclopenta[b]naphthalen-1-ylidene)malononitrile(NC), respectively. Benefiting from TPD core, which easily forms quinoid structure and O···H or O···S intramolecular noncovalent interactions, TPDCIC and TPDCNC show more delocalization of π-electrons and perfect planar molecular geometries, giving the absorption ranges extended to 822 and 852 nm, respectively. Furthermore, the highest occupied molecular orbital(HOMO) levels of TPDCIC and TPDCNC remain relatively low-lying due to the electronegativity of the carbonyl groups on TPD core. Considering that the absorptions and energy levels of the two NFAs match well with those of a widely used polymer donor, PBDB-T, we fabricate two kinds of organic solar cells(OSCs) based on the PBDB-T:TPDCIC and PBDB-T:TPDCNC blended films, respectively. Through a series of optimizations, the TPDCIC-based devices yield an impressing power conversion efficiency(PCE)of 10.12% with a large short-circuit current density(JSC) of 18.16 mA·cm-2, and the TPDCNC-based ones exhibit a comparable PCE of9.80% with a JSC of 17.40 mA·cm-2. Our work is the first report of the TPD-core-based A-D-A type NFAs, providing a good reference for the molecular design of high-performance NFAs.
