The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 ...The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 + is employed as an intermediate state to initiate resonance enhanced two-photon excitation to high-lying dissociative states in the 4.0-5.0 eV energy region above the ground rovibronic state. Total kinetic energy release (TKER) and the twodimensional recoiling velocity distributions of fragmented 79Br+ ions are measured using the technique of DC-slice velocity map imaging. Branching ratios for individual state-resolved product channels are determined from the TKER spectra. The measured photofragment angular distributions indicate that the dissociation of 79Br2 + occurs in dissociative Ω=3/2 state via ΔΩ=0 parallel transition from the 14Σ-u;3=2 intermediate state. Due to the considerable spin-orbit coupling effects in the excited states of 79Br2 +, higher-lying dissociative quartet states are likely responsible for the observed photodissociation processes.展开更多
基于无机CsPbI_(2)Br的碳基无空穴传输层钙钛矿太阳能电池(carbon based hole transport material freeperovskite solar cells,C-PSCs)具有成本低、易制备和稳定性好等优点而受到广泛关注。研究了空气环境下制备高效稳定的平面异质结Cs...基于无机CsPbI_(2)Br的碳基无空穴传输层钙钛矿太阳能电池(carbon based hole transport material freeperovskite solar cells,C-PSCs)具有成本低、易制备和稳定性好等优点而受到广泛关注。研究了空气环境下制备高效稳定的平面异质结CsPbI_(2)Br C-PSCs的2种制备工艺。首先,通过对反溶剂材料的种类及用量、钙钛矿前驱体溶液浓度等参数的优化,在反溶剂为800μL、钙钛矿前驱体溶液浓度为1.2 mol/L的条件下,采用一步溶液法成功制备了光电转换效率为9.87%的CsPbI_(2)Br C-PSCs。其次,为摆脱一步溶液法对有毒反溶剂的依赖,引入低温预退火工艺,通过对预退火时间及温度、钙钛矿前驱体溶液浓度等参数的优化,在空气环境下,预退火温度为80℃、钙钛矿前驱体溶液浓度为1.6 mol/L且未使用反溶剂的条件下获得了10.52%的最佳光电转化效率,同时CsPbI_(2)Br钙钛矿的退火温度可降低至240℃,并且未封装的器件在空气环境下显示出了较好的稳定性。展开更多
基金the National Natural Science Foundation of China(No.21773221 and No.21827804),the National Key R&D Program of China(2017YFA0303502),and Fundamental Research Funds for the Central Universities of China(WK2340000078).
文摘The [1+1] two-photon dissociation dynamics of mass-selected 79Br2 + has been studied in a cold ion beam using a cryogenic cylindrical ion trap velocity map imaging spectrometer. The quartet 14Σ- u;3=2 state of 79Br2 + is employed as an intermediate state to initiate resonance enhanced two-photon excitation to high-lying dissociative states in the 4.0-5.0 eV energy region above the ground rovibronic state. Total kinetic energy release (TKER) and the twodimensional recoiling velocity distributions of fragmented 79Br+ ions are measured using the technique of DC-slice velocity map imaging. Branching ratios for individual state-resolved product channels are determined from the TKER spectra. The measured photofragment angular distributions indicate that the dissociation of 79Br2 + occurs in dissociative Ω=3/2 state via ΔΩ=0 parallel transition from the 14Σ-u;3=2 intermediate state. Due to the considerable spin-orbit coupling effects in the excited states of 79Br2 +, higher-lying dissociative quartet states are likely responsible for the observed photodissociation processes.
基金supported by the National Natural Science Foundation of China(51708078,21576034)Chongqing Postdoctoral Science Foundation funded project(Xm2016027)the Innovative Research Team of Chongqing(CXTDG201602014,CXTDX201601016)~~
文摘基于无机CsPbI_(2)Br的碳基无空穴传输层钙钛矿太阳能电池(carbon based hole transport material freeperovskite solar cells,C-PSCs)具有成本低、易制备和稳定性好等优点而受到广泛关注。研究了空气环境下制备高效稳定的平面异质结CsPbI_(2)Br C-PSCs的2种制备工艺。首先,通过对反溶剂材料的种类及用量、钙钛矿前驱体溶液浓度等参数的优化,在反溶剂为800μL、钙钛矿前驱体溶液浓度为1.2 mol/L的条件下,采用一步溶液法成功制备了光电转换效率为9.87%的CsPbI_(2)Br C-PSCs。其次,为摆脱一步溶液法对有毒反溶剂的依赖,引入低温预退火工艺,通过对预退火时间及温度、钙钛矿前驱体溶液浓度等参数的优化,在空气环境下,预退火温度为80℃、钙钛矿前驱体溶液浓度为1.6 mol/L且未使用反溶剂的条件下获得了10.52%的最佳光电转化效率,同时CsPbI_(2)Br钙钛矿的退火温度可降低至240℃,并且未封装的器件在空气环境下显示出了较好的稳定性。
