Novel red-emitting phosphors Sr2MgSi2O7:Eu3+ were prepared by gel-combustion method assisted by microwave. The phase struc-ture and luminescent properties of as-synthesized phosphors were investigated by XRD and flu...Novel red-emitting phosphors Sr2MgSi2O7:Eu3+ were prepared by gel-combustion method assisted by microwave. The phase struc-ture and luminescent properties of as-synthesized phosphors were investigated by XRD and fluorescence spectrophotometer, respectively. The results showed that the as-synthesized sample was Sr2MgSi2O7 with tetragonal crystal structure. The excitation spectrum of Sr2MgSi2O7:Eu3+ was composed of two major parts: one was the broad band between 200 and 350 nm, which belonged to the charge transfer of Eu3+-O2-; the other consisted of a series of sharp lines between 350 and 450 nm, ascribed to the f-f transition of Eu3+. The emission spec-trum consisted of two emission peaks at 593 and 616 nm, which was attributed to 5D0→7F1 and 5D0→7F2 of Eu3+, respectively. The concen-tration of Eu3+ (x) had great effect on the emission intensity of Sr2-xMgSi2O7:Eu3+x. When x varied in the range of 0.04-0.18, the intensity of emission peaks at 593 and 616 nm increased gradually with the concentration of Eu3+ increasing. It was interesting that no concentration quenching occurred. Moreover, the luminescent intensity could be greatly enhanced with incorporation of charge compensator Li+ ions.展开更多
In the present study, graphene photonic crystals are employed to enhance the light extraction efficiency(LEE) of two-color, red and blue, light-emitting diode(LED). The transmission characteristics of one-dimensio...In the present study, graphene photonic crystals are employed to enhance the light extraction efficiency(LEE) of two-color, red and blue, light-emitting diode(LED). The transmission characteristics of one-dimensional(1D) Fibonacci graphene photonic crystal LED(FGPC-LED) are investigated by using the transfer matrix method and the scaling study is presented. We analyzed the influence of period, thickness, and permittivity in the structure to enhance the LEE. The transmission spectrum of 1D FGPC has been optimized in detail. In addition, the effects of the angle of incidence and the state of polarization are investigated. As the main result, we found the optimum values of relevant parameters to enhance the extraction of red and blue light from an LED as well as provide perfect omnidirectional and high peak transmission filters for the TE and TM modes.展开更多
针对低温多晶硅/有机发光二极管(Low Temperature Poly-Silicon/Organic Light-Emitting Diode,LTPS/OLED)玻璃基板厚度偏差控制难题,笔者研究了溢流下拉法中熔融玻璃性能、溢流砖结构、温度场及拉引工艺对厚度均匀性的影响机制,提出了...针对低温多晶硅/有机发光二极管(Low Temperature Poly-Silicon/Organic Light-Emitting Diode,LTPS/OLED)玻璃基板厚度偏差控制难题,笔者研究了溢流下拉法中熔融玻璃性能、溢流砖结构、温度场及拉引工艺对厚度均匀性的影响机制,提出了熔体性能调控、溢流砖结构优化、温度场精密控制及拉引稳定性强化的集成方案。中试结果显示:优化后玻璃基板厚度标准差由2.8μm降至0.9μm,最大厚度偏差降至±2.0μm以内,过程能力指数CPK达1.58,为超低厚度偏差显示玻璃制造提供技术范式,推动国产高端基板自主化。展开更多
针对基于加速模型参数不变、基于统计方法及基于试验观察3种常见的失效机理一致性检验方法进行研究,发现3种方法均需要加速试验数据来对失效机理一致性进行检验,不能事先为加速试验提供理论指导;提出了一种基于灰色理论的失效机理一致...针对基于加速模型参数不变、基于统计方法及基于试验观察3种常见的失效机理一致性检验方法进行研究,发现3种方法均需要加速试验数据来对失效机理一致性进行检验,不能事先为加速试验提供理论指导;提出了一种基于灰色理论的失效机理一致性检验方法,该方法可用预试验数据进行失效机理一致性检验,为加速试验制定最高应力台阶提供理论指导;结合某型光电编码器预试验数据对该方法进行实例验证,得出175℃附近为失效机理变化点,并与基于统计的方法进行对比;最后,对产品进行失效机理分析,利用扫描电镜分析(SEM,Scanning Electron Microscope)结果验证该方法的正确性.展开更多
基金Project supported by the National Natural Science Foundation of China (20675023)
摘要Novel red-emitting phosphors Sr2MgSi2O7:Eu3+ were prepared by gel-combustion method assisted by microwave. The phase struc-ture and luminescent properties of as-synthesized phosphors were investigated by XRD and fluorescence spectrophotometer, respectively. The results showed that the as-synthesized sample was Sr2MgSi2O7 with tetragonal crystal structure. The excitation spectrum of Sr2MgSi2O7:Eu3+ was composed of two major parts: one was the broad band between 200 and 350 nm, which belonged to the charge transfer of Eu3+-O2-; the other consisted of a series of sharp lines between 350 and 450 nm, ascribed to the f-f transition of Eu3+. The emission spec-trum consisted of two emission peaks at 593 and 616 nm, which was attributed to 5D0→7F1 and 5D0→7F2 of Eu3+, respectively. The concen-tration of Eu3+ (x) had great effect on the emission intensity of Sr2-xMgSi2O7:Eu3+x. When x varied in the range of 0.04-0.18, the intensity of emission peaks at 593 and 616 nm increased gradually with the concentration of Eu3+ increasing. It was interesting that no concentration quenching occurred. Moreover, the luminescent intensity could be greatly enhanced with incorporation of charge compensator Li+ ions.
摘要In the present study, graphene photonic crystals are employed to enhance the light extraction efficiency(LEE) of two-color, red and blue, light-emitting diode(LED). The transmission characteristics of one-dimensional(1D) Fibonacci graphene photonic crystal LED(FGPC-LED) are investigated by using the transfer matrix method and the scaling study is presented. We analyzed the influence of period, thickness, and permittivity in the structure to enhance the LEE. The transmission spectrum of 1D FGPC has been optimized in detail. In addition, the effects of the angle of incidence and the state of polarization are investigated. As the main result, we found the optimum values of relevant parameters to enhance the extraction of red and blue light from an LED as well as provide perfect omnidirectional and high peak transmission filters for the TE and TM modes.
摘要针对低温多晶硅/有机发光二极管(Low Temperature Poly-Silicon/Organic Light-Emitting Diode,LTPS/OLED)玻璃基板厚度偏差控制难题,笔者研究了溢流下拉法中熔融玻璃性能、溢流砖结构、温度场及拉引工艺对厚度均匀性的影响机制,提出了熔体性能调控、溢流砖结构优化、温度场精密控制及拉引稳定性强化的集成方案。中试结果显示:优化后玻璃基板厚度标准差由2.8μm降至0.9μm,最大厚度偏差降至±2.0μm以内,过程能力指数CPK达1.58,为超低厚度偏差显示玻璃制造提供技术范式,推动国产高端基板自主化。
摘要针对基于加速模型参数不变、基于统计方法及基于试验观察3种常见的失效机理一致性检验方法进行研究,发现3种方法均需要加速试验数据来对失效机理一致性进行检验,不能事先为加速试验提供理论指导;提出了一种基于灰色理论的失效机理一致性检验方法,该方法可用预试验数据进行失效机理一致性检验,为加速试验制定最高应力台阶提供理论指导;结合某型光电编码器预试验数据对该方法进行实例验证,得出175℃附近为失效机理变化点,并与基于统计的方法进行对比;最后,对产品进行失效机理分析,利用扫描电镜分析(SEM,Scanning Electron Microscope)结果验证该方法的正确性.