All-inorganic CsPbI_(3)quantum dots(QDs)exhibit remarkable optoelectronic properties,identifying them as promising candidates for advanced display materials.However,achieving pure-red emission from CsPbI_(3)QDs remain...All-inorganic CsPbI_(3)quantum dots(QDs)exhibit remarkable optoelectronic properties,identifying them as promising candidates for advanced display materials.However,achieving pure-red emission from CsPbI_(3)QDs remains a significant challenge due to limitations in bandgap tuning using conventional high-temperature hot-injection methods.Introducing A-site cations,such as ethylammonium(EA^(+)),has been shown to modulate near-edge states by inducing lattice distortions.Nevertheless,the thermal instability of EA^(+)salts at high temperatures poses a major obstacle in achieving stable doping.To address this challenge,we harnessed the acid-base equilibrium between ethylammonium salts and oleic acid in the cesium precursor,enabling the in situ formation of thermally stable ethylammonium oleate.This innovation allowed the precise tuning of the emission wavelength within 630–650 nm by controlling EA^(+)doping levels.After optimization of the EA^(+)doping concentration and device architecture,pure-red perovskite light-emitting diodes were achieved with an external quantum efficiency up to 26.1%.Our findings present a groundbreaking methodology for bandgap engineering of CsPbI_(3)QDs,providing pivotal insights for the development of advanced perovskite optoelectronic materials and devices.展开更多
The quality of the perovskite light absorption layer plays a dynamic role in the photovoltaic properties of solar cells.The existing methods to prepare methylammonium lead iodide(MAPbI3)films render substantial struct...The quality of the perovskite light absorption layer plays a dynamic role in the photovoltaic properties of solar cells.The existing methods to prepare methylammonium lead iodide(MAPbI3)films render substantial structural defect density,particularly at the grain boundaries and film surface,constituting a challenge that hinders the further optoelectronic enhancement of perovskite solar cells.Herein,a unique approach was introduced:using a simple ethylammonium chloride(EACl)additive in perovskite precursor mixture to produce high-quality MAPbI3 thin films.The results indicated that EACl could encourage perovskite crystal growth without experiencing the intermediate phase formation and would evaporate from the perovskite after annealing.Additionally,a gradient perovskite structure was achieved using this technique,which impressively enhanced the performance of the perovskite films.A high power conversion efficiency(PCE)of 20.03%was achieved under the optimal amount of EACl,and the resultant efficient device could retain over 89%of the original PCE after aging for 1000 h at room temperature.This novel technique leads to a facile fabrication of highquality and less-defect perovskite thin films for competent and stable devices.展开更多
The mixed-cation lead halide perovskites have emerged as a new class of promising light harvesting materials for solar cells. The formamidinium（FA）, methylammonium（MA） and Cs cations are widely studied in the fiel...The mixed-cation lead halide perovskites have emerged as a new class of promising light harvesting materials for solar cells. The formamidinium（FA）, methylammonium（MA） and Cs cations are widely studied in the field of mixed-cation perovskites. Here, we have investigated ethylammonium（EA） as an alternative cation to fabricate a mixed-cation perovskite of MA_（1-x）EA_xPbI_3. We have characterized the materials using the X-ray diffraction（XRD）, scanning electron microscope（SEM）, and UV–vis spectrum. Our results have confirmed the successful incorporation of EA cations into MAPbI_3. Interestingly, the optimal amount of EA to achieve the best performance is quite low. This is different from the FA–MA mixed-cation perovskites although EA and FA have similar radii. In short, the EA–MA mixed-cation perovskite has some material and device properties highly distinguishable from the FA–MA one.展开更多
为得到适用于硝酸乙基铵(Ethylammonium nitrate,EAN)推力器燃烧数值模拟的燃烧机理,以包含EAN蒸发产物硝酸和乙胺的详细化学反应机理为基础,构建了EAN详细燃烧机理,采用生产速率(Rate of production,ROP)分析以及敏感性分析相结合的方...为得到适用于硝酸乙基铵(Ethylammonium nitrate,EAN)推力器燃烧数值模拟的燃烧机理,以包含EAN蒸发产物硝酸和乙胺的详细化学反应机理为基础,构建了EAN详细燃烧机理,采用生产速率(Rate of production,ROP)分析以及敏感性分析相结合的方法对详细机理进行简化,得到了包含82组分291反应的EAN燃烧骨架机理。分别使用两种机理对乙胺着火延迟时间、层流预混火焰中组分分布以及在激波管内反应过程中组分分布,硝酸在激波管内反应过程中组分分布进行了数值模拟,通过比较实验数据和模拟结果,对详细机理和骨架机理进行验证。验证结果表明:骨架机理的模拟结果与实验数据以及详细机理的模拟结果一致,表明了EAN燃烧骨架机理的准确性。得到的骨架机理为EAN推力器燃烧数值模拟提供了反应机理模型。展开更多
基金supported by the National Natural Science Foundation of China(52172160,21805181,22375179,and U22A20133)the Fundamental Research Funds for the Provincial Universities of Zhejiang(RF-C2022005)+1 种基金the National Key Research and Development Project of China(2023YFB3608902)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2024C01191).
文摘All-inorganic CsPbI_(3)quantum dots(QDs)exhibit remarkable optoelectronic properties,identifying them as promising candidates for advanced display materials.However,achieving pure-red emission from CsPbI_(3)QDs remains a significant challenge due to limitations in bandgap tuning using conventional high-temperature hot-injection methods.Introducing A-site cations,such as ethylammonium(EA^(+)),has been shown to modulate near-edge states by inducing lattice distortions.Nevertheless,the thermal instability of EA^(+)salts at high temperatures poses a major obstacle in achieving stable doping.To address this challenge,we harnessed the acid-base equilibrium between ethylammonium salts and oleic acid in the cesium precursor,enabling the in situ formation of thermally stable ethylammonium oleate.This innovation allowed the precise tuning of the emission wavelength within 630–650 nm by controlling EA^(+)doping levels.After optimization of the EA^(+)doping concentration and device architecture,pure-red perovskite light-emitting diodes were achieved with an external quantum efficiency up to 26.1%.Our findings present a groundbreaking methodology for bandgap engineering of CsPbI_(3)QDs,providing pivotal insights for the development of advanced perovskite optoelectronic materials and devices.
基金supported by the National Key R&D Program of China(2019YFB1503202)the 111 Project(B16016)+1 种基金the National Natural Science Foundation of China(51702096,U1705256 and 61904053)the Fundamental Research Funds for the Central Universities(2019MS026,2019MS027 and 2020MS080)。
文摘The quality of the perovskite light absorption layer plays a dynamic role in the photovoltaic properties of solar cells.The existing methods to prepare methylammonium lead iodide(MAPbI3)films render substantial structural defect density,particularly at the grain boundaries and film surface,constituting a challenge that hinders the further optoelectronic enhancement of perovskite solar cells.Herein,a unique approach was introduced:using a simple ethylammonium chloride(EACl)additive in perovskite precursor mixture to produce high-quality MAPbI3 thin films.The results indicated that EACl could encourage perovskite crystal growth without experiencing the intermediate phase formation and would evaporate from the perovskite after annealing.Additionally,a gradient perovskite structure was achieved using this technique,which impressively enhanced the performance of the perovskite films.A high power conversion efficiency(PCE)of 20.03%was achieved under the optimal amount of EACl,and the resultant efficient device could retain over 89%of the original PCE after aging for 1000 h at room temperature.This novel technique leads to a facile fabrication of highquality and less-defect perovskite thin films for competent and stable devices.
基金the support of the NSFC(Grant 51372151 and21303103)Huoyingdong Grant(151046)
文摘The mixed-cation lead halide perovskites have emerged as a new class of promising light harvesting materials for solar cells. The formamidinium（FA）, methylammonium（MA） and Cs cations are widely studied in the field of mixed-cation perovskites. Here, we have investigated ethylammonium（EA） as an alternative cation to fabricate a mixed-cation perovskite of MA_（1-x）EA_xPbI_3. We have characterized the materials using the X-ray diffraction（XRD）, scanning electron microscope（SEM）, and UV–vis spectrum. Our results have confirmed the successful incorporation of EA cations into MAPbI_3. Interestingly, the optimal amount of EA to achieve the best performance is quite low. This is different from the FA–MA mixed-cation perovskites although EA and FA have similar radii. In short, the EA–MA mixed-cation perovskite has some material and device properties highly distinguishable from the FA–MA one.
文摘为得到适用于硝酸乙基铵(Ethylammonium nitrate,EAN)推力器燃烧数值模拟的燃烧机理,以包含EAN蒸发产物硝酸和乙胺的详细化学反应机理为基础,构建了EAN详细燃烧机理,采用生产速率(Rate of production,ROP)分析以及敏感性分析相结合的方法对详细机理进行简化,得到了包含82组分291反应的EAN燃烧骨架机理。分别使用两种机理对乙胺着火延迟时间、层流预混火焰中组分分布以及在激波管内反应过程中组分分布,硝酸在激波管内反应过程中组分分布进行了数值模拟,通过比较实验数据和模拟结果,对详细机理和骨架机理进行验证。验证结果表明:骨架机理的模拟结果与实验数据以及详细机理的模拟结果一致,表明了EAN燃烧骨架机理的准确性。得到的骨架机理为EAN推力器燃烧数值模拟提供了反应机理模型。
