A new approach to the massive production of TiC whiskers with high purity and low cost was presented. It is a modified carbothermal reduction method (MCTR) characterized by argon stream flowing vertically and passin...A new approach to the massive production of TiC whiskers with high purity and low cost was presented. It is a modified carbothermal reduction method (MCTR) characterized by argon stream flowing vertically and passing through the interior of the mixture of raw materials. It is found for the first time that there is an optimum flow of the upward flowing argon stream, at which large quantity of high quality TiC can be obtained. This paper described the new method, analyzed the mechanism and conditions for the formation of high purity TiC whiskers on a large scale, and compared MCTR with the traditional carbothermal reduction method (TCTR). Based on the analysis and comparison, it is concluded that in order to produce high quality transition metal carbides, nitrides and carbonitrides with low cost TCTR must be replaced by MCTR.展开更多
Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blen...Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blend films and relevant effects on device performances,including as-cast,thermal annealing and solvent annealing.This solvent annealing processes can effectively improve the vertical distribution and aggregation of polymer donors and small molecule acceptors,then optimize the active layer film morphology,ultimately elevating PCE.Thus,one of champion efficiencies of 18.01%was achieved based on the PM6:Y6 binary OSCs.In addition,a relatively high light utilization efficiency(2.53%)was achieved when a transparent electrode made of Cu(1 nm)and Ag(15 nm)was utilized to fabricate a semitransparent OSC with a remarkable PCE of 13.07%and 19.33%average visible-light transmittance.These results demonstrated that carefully optimizing morphology of active layer is conducive to achieving a high-performance OSC.展开更多
All-inorganic perovskite solar cells(PSCs)have developed rapidly in the field of photovoltaics due to their excellent thermal and light stability.However,compared with organic–inorganic hybrid perovskites,the phase i...All-inorganic perovskite solar cells(PSCs)have developed rapidly in the field of photovoltaics due to their excellent thermal and light stability.However,compared with organic–inorganic hybrid perovskites,the phase instability of inorganic perovskite under humidity still remains as a critical issue that ham-pers the commercialization of inorganic PSCs.We originally propose in this work that microstrains between the perovskite lattices/grains play a key role in affecting the phase stability of inorganic perovskite.To this end,we inno-vatively design theπ-conjugated p-type molecule bis(2-ethylhexyl)3,30((4,8-bis(5-(2-ethylhexyl)-3,4-difluorothiophen-2-yl)benzo[1,2-b:4,5-b0]dithiophene-2,6-di yl)bis(3,300-dioctyl[2,20:50,200-terthiophene]-500,5-diyl))(2E,20 E)-bis(2-cyanoacrylate)(BTEC-2F)to covalent with the Pb dangling bonds in CsPbI2Br perovskite film,which significantly suppress the trap states and release the defect-induced local stress between perovskite grains.The interplay between the microstrains and phase stability of the inorganic perovskite are scrutinized by a series of charac-terizations including x-ray photoelectron spectroscopy,photoluminescence,x-ray diffraction,scanning electron microscopy,and so forth,based on which,we conclude that weaker local stresses in the perovskite film engender superior phase stability by preventing the perovskite lattice distortion under humidity.By this rational design,PSCs based on CsPbI2Br perovskite system deliver an outstanding power conversion efficiency(PCE)up to 16.25%.The unencapsulated device also exhibits an exceptional moisture stability by retaining over 80%of the initial PCE after 500 h aging in ambient with relative humidity of(RH)25%.展开更多
文摘A new approach to the massive production of TiC whiskers with high purity and low cost was presented. It is a modified carbothermal reduction method (MCTR) characterized by argon stream flowing vertically and passing through the interior of the mixture of raw materials. It is found for the first time that there is an optimum flow of the upward flowing argon stream, at which large quantity of high quality TiC can be obtained. This paper described the new method, analyzed the mechanism and conditions for the formation of high purity TiC whiskers on a large scale, and compared MCTR with the traditional carbothermal reduction method (TCTR). Based on the analysis and comparison, it is concluded that in order to produce high quality transition metal carbides, nitrides and carbonitrides with low cost TCTR must be replaced by MCTR.
基金supported by the National Science Fund for Distinguished Young Scholars(21925506)the National Natural Science Foundation of China(U21A20331,51773212,81903743,51875384)+2 种基金Ningbo S&T Innovation 2025 Major Special Programme(2018B10055)CAS Key Project of Frontier Science Research(QYZDBSSW-SYS030)Ningbo Natural Science Foundation(2021J192)。
文摘Optimizing the photoactive layer morphology is a simple,promising way to improve the power conversion efficiencies(PCEs)of organic solar cells(OSCs).Here,we compared different post-processing treatments on PM6:Y6 blend films and relevant effects on device performances,including as-cast,thermal annealing and solvent annealing.This solvent annealing processes can effectively improve the vertical distribution and aggregation of polymer donors and small molecule acceptors,then optimize the active layer film morphology,ultimately elevating PCE.Thus,one of champion efficiencies of 18.01%was achieved based on the PM6:Y6 binary OSCs.In addition,a relatively high light utilization efficiency(2.53%)was achieved when a transparent electrode made of Cu(1 nm)and Ag(15 nm)was utilized to fabricate a semitransparent OSC with a remarkable PCE of 13.07%and 19.33%average visible-light transmittance.These results demonstrated that carefully optimizing morphology of active layer is conducive to achieving a high-performance OSC.
基金CAS Key Project of Frontier Science Research,Grant/Award Number:QYZDBSSW-SYS030National Natural Science Foundation of China,Grant/Award Numbers:22005322,51773212,81903743+2 种基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:21925506Ningbo S&T Innovation 2025 Major Special Programme,Grant/Award Number:2018B10055National Key R&D Program of China,Grant/Award Number:2017YFE0106000。
文摘All-inorganic perovskite solar cells(PSCs)have developed rapidly in the field of photovoltaics due to their excellent thermal and light stability.However,compared with organic–inorganic hybrid perovskites,the phase instability of inorganic perovskite under humidity still remains as a critical issue that ham-pers the commercialization of inorganic PSCs.We originally propose in this work that microstrains between the perovskite lattices/grains play a key role in affecting the phase stability of inorganic perovskite.To this end,we inno-vatively design theπ-conjugated p-type molecule bis(2-ethylhexyl)3,30((4,8-bis(5-(2-ethylhexyl)-3,4-difluorothiophen-2-yl)benzo[1,2-b:4,5-b0]dithiophene-2,6-di yl)bis(3,300-dioctyl[2,20:50,200-terthiophene]-500,5-diyl))(2E,20 E)-bis(2-cyanoacrylate)(BTEC-2F)to covalent with the Pb dangling bonds in CsPbI2Br perovskite film,which significantly suppress the trap states and release the defect-induced local stress between perovskite grains.The interplay between the microstrains and phase stability of the inorganic perovskite are scrutinized by a series of charac-terizations including x-ray photoelectron spectroscopy,photoluminescence,x-ray diffraction,scanning electron microscopy,and so forth,based on which,we conclude that weaker local stresses in the perovskite film engender superior phase stability by preventing the perovskite lattice distortion under humidity.By this rational design,PSCs based on CsPbI2Br perovskite system deliver an outstanding power conversion efficiency(PCE)up to 16.25%.The unencapsulated device also exhibits an exceptional moisture stability by retaining over 80%of the initial PCE after 500 h aging in ambient with relative humidity of(RH)25%.