Hf_(0.5)Zr_(0.5)O_(2)(HZO)ferroelectric thin films have gained significant attention for the development of next-generation ferroelectric memories by complementary-metal-oxide semiconductor(CMOS)back-end-of-line(BEOL)...Hf_(0.5)Zr_(0.5)O_(2)(HZO)ferroelectric thin films have gained significant attention for the development of next-generation ferroelectric memories by complementary-metal-oxide semiconductor(CMOS)back-end-of-line(BEOL)processing,due to their relatively low crystallization temperature.However,it remains challenging to achieve excellent ferroelectric properties with post deposition annealing(PDA)process at a BEOL compatible temperature.Along these lines,in this work,it is demonstrated that the ferroelec-tricity of 15 nm thick HZO thin film prepared by PDA process at 400℃can be improved to varying degrees,via depositing 2 nm thick dielectric layers of Al_(2)O_(3),HfO_(2),or ZrO_(2)at either the bottom or the top of the film.Notably,the HZO thin film with the top-Al_(2)O_(3)layer exhibits remarkable ferroelectric prop-erties,which are independent of the thickness of HZO.The 6 nm thick HZO thin film shows a total remanent polarization(2Pr)of 31 mC/cm^(2)under an operating voltage of 2.5 V.These results represent a significant advancement in the fabrication of high-performance,BEOL compatible ferroelectric mem-ories,as compared to previously reported state-of-the-art works.展开更多
Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while ...Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while their trace residues may reduce device stability.Herein,an effective strategy of“solidification of solvent additive(SSA)”has been developed to convert additive from liquid to solid,by introducing a covalent bond into low-cost solvent diphenyl sulfide(DPS)to synthesize solid dibenzothiophene(DBT)in one-step,which achieves optimized morphology thus promoting efficiency and device stability.Owing to the fine planarity and volatilization of DBT,the DBT-processed films achieve ordered molecular crystallinity and suitable phase separation compared to the additive-free or DPS-treated ones.Importantly,the DBT-processed device also possesses improved light absorption,enhanced charge transport,and thus a champion efficiency of 17.9%is achieved in the PM6:Y6-based PSCs with an excellent additive component tolerance,reproducibility,and stability.Additionally,the DBT-processed PM6:L8-BO-based PSCs are further fabricated to study the universality of SSA strategy,offering an impressive efficiency approaching19%as one of the highest values in binary PSCs.In conclusion,this article developed a promising strategy named SSA to boost efficiency and improve stability of PSCs.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.52122205,52102147,52072324,11932016)the China Postdoctoral Science Foundation(2022M712674).
文摘Hf_(0.5)Zr_(0.5)O_(2)(HZO)ferroelectric thin films have gained significant attention for the development of next-generation ferroelectric memories by complementary-metal-oxide semiconductor(CMOS)back-end-of-line(BEOL)processing,due to their relatively low crystallization temperature.However,it remains challenging to achieve excellent ferroelectric properties with post deposition annealing(PDA)process at a BEOL compatible temperature.Along these lines,in this work,it is demonstrated that the ferroelec-tricity of 15 nm thick HZO thin film prepared by PDA process at 400℃can be improved to varying degrees,via depositing 2 nm thick dielectric layers of Al_(2)O_(3),HfO_(2),or ZrO_(2)at either the bottom or the top of the film.Notably,the HZO thin film with the top-Al_(2)O_(3)layer exhibits remarkable ferroelectric prop-erties,which are independent of the thickness of HZO.The 6 nm thick HZO thin film shows a total remanent polarization(2Pr)of 31 mC/cm^(2)under an operating voltage of 2.5 V.These results represent a significant advancement in the fabrication of high-performance,BEOL compatible ferroelectric mem-ories,as compared to previously reported state-of-the-art works.
基金the financial support from the Scientific Research Project of Education Department of Hunan Province(21C0091)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices(South China University of Technology)(2023skllmd-13)+6 种基金the support from the National Natural Science Foundation of China(22209131,22005121)the open fund support from School of Materials Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications(GDRGCS2021002,GDRGCS2022003,GDRGCS2022002)the support from the National Key Research and Development Program of China(2022YFE0132400)the National Natural Science Foundation of China(21875182,52173023)the Key Scientific and Technological Innovation Team Project of Shaanxi Province(2020TD-002)111 Project 2.0(BP0618008)supported by the Director,Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy(DE-AC0205CH11231)。
文摘Additives play a crucial role in enhancing the photovoltaic performance of polymer solar cells(PSCs).However,the typical additives used to optimize blend morphology of PSCs are still high boiling-point solvents,while their trace residues may reduce device stability.Herein,an effective strategy of“solidification of solvent additive(SSA)”has been developed to convert additive from liquid to solid,by introducing a covalent bond into low-cost solvent diphenyl sulfide(DPS)to synthesize solid dibenzothiophene(DBT)in one-step,which achieves optimized morphology thus promoting efficiency and device stability.Owing to the fine planarity and volatilization of DBT,the DBT-processed films achieve ordered molecular crystallinity and suitable phase separation compared to the additive-free or DPS-treated ones.Importantly,the DBT-processed device also possesses improved light absorption,enhanced charge transport,and thus a champion efficiency of 17.9%is achieved in the PM6:Y6-based PSCs with an excellent additive component tolerance,reproducibility,and stability.Additionally,the DBT-processed PM6:L8-BO-based PSCs are further fabricated to study the universality of SSA strategy,offering an impressive efficiency approaching19%as one of the highest values in binary PSCs.In conclusion,this article developed a promising strategy named SSA to boost efficiency and improve stability of PSCs.
