To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scan...To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.展开更多
The use of organic hole transport layer(HTL)Spiro-OMeTAD in various solar cells imposes serious stabil-ity and cost problems,and thus calls for inorganic substitute materials.In this work,a novel inorganic MnS film pr...The use of organic hole transport layer(HTL)Spiro-OMeTAD in various solar cells imposes serious stabil-ity and cost problems,and thus calls for inorganic substitute materials.In this work,a novel inorganic MnS film prepared by thermal evaporation has been demonstrated to serve as a decent HTL in high-performance Sb_(2)(S,Se)_(3)solar cells,providing a cost-effective all-inorganic solution.A low-temperature air-annealing process for the evaporated MnS layer was found to result in a significant positive effect on the power conversion efficiency(PCE)of Sb_(2)(S,Se)_(3)solar cells,due to its better-matched energy band alignment after partial oxidation.Impressively,the device with the optimized MnS HTL has achieved an excellent PCE of about 9.24%,which is the highest efficiency among all-inorganic Sb_(2)(S,Se)_(3)solar cells.Our result has revealed that MnS is a feasible substitute for organic HTL in Sb-based solar cells to achieve high PCE,low cost,and high stability.展开更多
Nano-ZnO thin films composed of nanoparticles with sizes of 10-16 nm on silicon substrates at low temperature were prepared by sol-gel method.By placing the nano-ZnO thin films at room temperature or annealing at 100&...Nano-ZnO thin films composed of nanoparticles with sizes of 10-16 nm on silicon substrates at low temperature were prepared by sol-gel method.By placing the nano-ZnO thin films at room temperature or annealing at 100°C in air for 10 h intermittently,within a total 70 h annealing time,the evolution of PL spectra of the nano-ZnO thin films were studied in detail.As the annealing time increases,the PL peaks shift from violet to blue and green bands.The PL peaks at violet and blue bands decrease with the annealing time,but the PL peaks at green band are opposite.The PL spectra are related to the defects in the nano-ZnO thin films.The PL peaks positioned at 430 nm are mainly related to defects of zinc interstatials(Zni),oxygen vacancies and(Vo);the ones at 420 nm to oxygen interstitials(Oi),Zinc vacancies(Vzn),Zni ;and the ones at 468 nm to Vzn,Zni,and charged oxygen interstatials(Vo+).The green luminescence is related to Oi,Vo and Zni.The evolutions of PL spectra and the defects are also related to the concentrations of Zn in the thin films,the thicknesses of the films and the annealing time.For the films with 0.5 M and 1.0 M Zn concentrations,after 20 h and 30 h annealing in air at 100°C,respectively,either placing them in air at room temperature or continuing anneal in air at 100°C,the PL spectra are stable.Under the low temperature annealing,Zni decreases with the annealing time,and Oi increases.Sufficient Oi favors to keep the nano-ZnO thin films stable.This result is important to nano-ZnO thin films as electron transport layers in inverted or tandem organic solar cells.展开更多
基金Project(2009D005002000003) supported by the Foundation for Fostering Outstanding Talents of Beijing,China
文摘To study the mechanics of work-hardening and annealing-softening, a series of experiments were conducted on samples of 304 austenitic stainless steel sheets. In addition, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, and tensile testing were carried out to study changes and mechanisms of the stainless steel structures and properties during work-hardening and annealing-softening. The results indicate that annealing at low temperatures （100-500 ~C） can only remove partial residual stresses in the sample and the softening via annealing is not obvious. Bright annealing and rapid cooling in a protective atmosphere can completely soften the cold-worked material. In addition, the low-temperature sample without a protective atmosphere only has a little oxidation on the surface, but at higher temperature the oxidized layer is very thick. Thus, high-temperature annealing should include bright annealing.
基金the Science and Technology Department of Hubei Province(2019AAA020)Wuhan Science and Technology Project of China(2019010701011420)+1 种基金Fundamental Research Funds for the Central University(2042021kf0069)the National Natural Science Foundation of China(61974028)。
文摘The use of organic hole transport layer(HTL)Spiro-OMeTAD in various solar cells imposes serious stabil-ity and cost problems,and thus calls for inorganic substitute materials.In this work,a novel inorganic MnS film prepared by thermal evaporation has been demonstrated to serve as a decent HTL in high-performance Sb_(2)(S,Se)_(3)solar cells,providing a cost-effective all-inorganic solution.A low-temperature air-annealing process for the evaporated MnS layer was found to result in a significant positive effect on the power conversion efficiency(PCE)of Sb_(2)(S,Se)_(3)solar cells,due to its better-matched energy band alignment after partial oxidation.Impressively,the device with the optimized MnS HTL has achieved an excellent PCE of about 9.24%,which is the highest efficiency among all-inorganic Sb_(2)(S,Se)_(3)solar cells.Our result has revealed that MnS is a feasible substitute for organic HTL in Sb-based solar cells to achieve high PCE,low cost,and high stability.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41172110,61107090)Shandong Provincial Natural Science Foundation (Grant No. ZR2011BZ007)
文摘Nano-ZnO thin films composed of nanoparticles with sizes of 10-16 nm on silicon substrates at low temperature were prepared by sol-gel method.By placing the nano-ZnO thin films at room temperature or annealing at 100°C in air for 10 h intermittently,within a total 70 h annealing time,the evolution of PL spectra of the nano-ZnO thin films were studied in detail.As the annealing time increases,the PL peaks shift from violet to blue and green bands.The PL peaks at violet and blue bands decrease with the annealing time,but the PL peaks at green band are opposite.The PL spectra are related to the defects in the nano-ZnO thin films.The PL peaks positioned at 430 nm are mainly related to defects of zinc interstatials(Zni),oxygen vacancies and(Vo);the ones at 420 nm to oxygen interstitials(Oi),Zinc vacancies(Vzn),Zni ;and the ones at 468 nm to Vzn,Zni,and charged oxygen interstatials(Vo+).The green luminescence is related to Oi,Vo and Zni.The evolutions of PL spectra and the defects are also related to the concentrations of Zn in the thin films,the thicknesses of the films and the annealing time.For the films with 0.5 M and 1.0 M Zn concentrations,after 20 h and 30 h annealing in air at 100°C,respectively,either placing them in air at room temperature or continuing anneal in air at 100°C,the PL spectra are stable.Under the low temperature annealing,Zni decreases with the annealing time,and Oi increases.Sufficient Oi favors to keep the nano-ZnO thin films stable.This result is important to nano-ZnO thin films as electron transport layers in inverted or tandem organic solar cells.
