Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3...Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3（A = CH_3NH_3; B = Sn,Pb; X = Cl, Br, I） and provide the best absorber among ABX_3 when the organic framework A is CH_3NH_3 by first-principles calculations. The results reveal that the valence band maximum（VBM） of the ABX_3 is mainly composed of anion X p states and that conduction band minimum（CBM） of the ABX_3 is primarily composed of cation B p states. The bandgap of the ABX_3 decreases and the absorptive capacities of different wavelengths of light expand when reducing the size of the organic framework A, changing the B atom from Pb to Sn, and changing the X atom from Cl to Br to I. Finally, based on our calculations, it is discovered that CH_3NH_3 Sn I_3has the best optical properties and its light-adsorption range is the widest among all the ABX_3 compounds when A is CH_3NH_3. All these results indicate that the electronegativity difference between X and B plays a fundamental role in changing the energy gap and optical properties among ABX_3 compounds when A remains the same and that CH_3NH_3 Sn I_3 is a promising perovskite absorber in the high efficiency solar batteries among all the CH_3NH_3BX_3 compounds.展开更多
Anti-Markovnikov hydroazidation of unactivated alkenes using ABX–N3 as an initiator has been developed at room temperature,wherein hydrogen azide(HN3)acts as both hydrogen and azidating agent.Notably,the HN3 reagent ...Anti-Markovnikov hydroazidation of unactivated alkenes using ABX–N3 as an initiator has been developed at room temperature,wherein hydrogen azide(HN3)acts as both hydrogen and azidating agent.Notably,the HN3 reagent was generated from azidotrimethylsilane(TMSN3)and acetic acid in situ.The reaction itself displays broad substrate scope,good yields and excellent regioselectivities.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61366007,11164032,and 61066005)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-12-1080)+1 种基金the Basic Applied Research Foundation of Yunnan Province,China(Grant Nos.2011CI003 and 2013FB007)the Excellent Young Talents in Yunnan University,China
文摘Organic–inorganic hybrid perovskites play an important role in improving the efficiency of solid-state dye-sensitized solar cells. In this paper, we systematically explore the efficiency-enhancing mechanism of ABX_3（A = CH_3NH_3; B = Sn,Pb; X = Cl, Br, I） and provide the best absorber among ABX_3 when the organic framework A is CH_3NH_3 by first-principles calculations. The results reveal that the valence band maximum（VBM） of the ABX_3 is mainly composed of anion X p states and that conduction band minimum（CBM） of the ABX_3 is primarily composed of cation B p states. The bandgap of the ABX_3 decreases and the absorptive capacities of different wavelengths of light expand when reducing the size of the organic framework A, changing the B atom from Pb to Sn, and changing the X atom from Cl to Br to I. Finally, based on our calculations, it is discovered that CH_3NH_3 Sn I_3has the best optical properties and its light-adsorption range is the widest among all the ABX_3 compounds when A is CH_3NH_3. All these results indicate that the electronegativity difference between X and B plays a fundamental role in changing the energy gap and optical properties among ABX_3 compounds when A remains the same and that CH_3NH_3 Sn I_3 is a promising perovskite absorber in the high efficiency solar batteries among all the CH_3NH_3BX_3 compounds.
基金supported by the National Basic Research Program of China(973-2015CB856600)the National Natural Science Foundation of China(21532009,21821002,21790330,21761142010)+2 种基金the Science and Technology Commission of Shanghai Municipality(17XD1404500,17QA1405200,17JC1401200)the strategic Priority Research Program(XDB20000000)the Key Research Program of Frontier Science(QYZDJSSW-SLH055)of the Chinese Academy of Sciences
文摘Anti-Markovnikov hydroazidation of unactivated alkenes using ABX–N3 as an initiator has been developed at room temperature,wherein hydrogen azide(HN3)acts as both hydrogen and azidating agent.Notably,the HN3 reagent was generated from azidotrimethylsilane(TMSN3)and acetic acid in situ.The reaction itself displays broad substrate scope,good yields and excellent regioselectivities.
