45579-91-7Relevant academic research and scientific papers
Improved Performance of Printable Perovskite Solar Cells with Bifunctional Conjugated Organic Molecule
Hu, Yue,Zhang, Zhihui,Mei, Anyi,Jiang, Youyu,Hou, Xiaomeng,Wang, Qifei,Du, Kai,Rong, Yaoguang,Zhou, Yinhua,Xu, Gengzhao,Han, Hongwei
, (2018/02/06)
A bifunctional conjugated organic molecule 4-(aminomethyl) benzoic acid hydroiodide (AB) is designed and employed as an organic cation in organic–inorganic halide perovskite materials. Compared with the monofunctional cation benzylamine hydroiodide (BA) and the nonconjugated bifunctional organic molecule 5-ammonium valeric acid, devices based on AB-MAPbI3 show a good stability and a superior power conversion efficiency of 15.6% with a short-circuit current of 23.4 mA cm?2, an open-circuit voltage of 0.94 V, and a fill factor of 0.71. The bifunctional conjugated cation not only benefits the growth of perovskite crystals in the mesoporous network, but also facilitates the charge transport. This investigation helps explore new approaches to rational design of novel organic cations for perovskite materials.
Syntheses of needle-shaped layered perovskite (C6H5CH2NH3)2PbI4bundles via a two-step processing technique
Ma, Dewei,He, Yidan
, p. 1213 - 1219 (2016/12/22)
Similar to the three-dimensional perovskites, two-dimensional (2D) layered lead halide perovskites constitute a particular class of semiconductor materials in the family of perovskites. This article reports syntheses of needle-like bundles of 2D perovskite (C6H5CH2NH3)2PbI4by a two-step processing technique. The concentration of C6H5CH2NH3I precursor has a great influence on the product, structural and compositional analyses prove the phase and stoichiometry of 2D perovskite (C6H5CH2NH3)2PbI4with high crystallinity for the needle bundles synthesized with concentration of C6H5CH2NH3I higher than 25 mg/mL. Intensive studies on the growth mechanism of the products were carried out; we believe the involvement of C6H5CH2NH3+group determines the layered structure and the final morphology of the products. Photoluminescence measurement show that the needles possess a band-edge emission peak centering around 540 nm and a narrow full width at half maximum of about 30 nm.
Ammonium-iodide-salt additives induced photovoltaic performance enhancement in one-step solution process for perovskite solar cells
Yang,Song,Zhao,Zhu,Gu,Gu,Che,Qiang,Song
, p. 84 - 90 (2016/06/06)
Unordered aggregation of perovskite particles on TiO2 mesoporous film surface is a common problem in one-step solution process for fabricating perovskite solar cells (PSCs). This phenomenon is harmful for homogeneous dispersion of perovskite in mesoporous TiO2 film and responsible for the low photovoltaic performance of corresponding perovskite solar cells at the same time. Delicate control of perovskite nucleation and growth is an effective route to solve this problem. In this work, we proposed a facile strategy to improve perovskite (CH3NH3PbI3) growth by adding C6H5CH2NH3I (BAI) or NH4I ionic compounds in perovskite precursor solution. We investigated perovskite crystal structure and morphology, optical and electrochemical properties of perovskite films or devices using different additives by XRD, SEM, UV-Vis, IPCE, and EIS. We found that these additives could decrease the grain size of perovskite crystal and diminish perovskite particle aggregation on TiO2 film surface. This effect is benefit for electron transfer on perovskite/TiO2 interface. Finally, perovskite solar cells using BAI or NH4I additives obtain the best solar-to-electricity conversion efficiency of 9.05% and 9.49%, respectively, which are much higher than that of the pristine one, 6.83%.
Convenient synthesis of cyclic carbonates from CO2 and epoxides by simple secondary and primary ammonium iodides as metal-free catalysts under mild conditions and its application to synthesis of polymer bearing cyclic carbonate moiety
Aoyagi, Naoto,Furusho, Yoshio,Endo, Takeshi
, p. 1230 - 1242 (2013/03/29)
Hydroiodides of secondary and primary amines effectively catalyzed the reaction of carbon dioxide and epoxides under mild conditions such as ordinary pressure and ambient temperature, to obtain the corresponding five-membered cyclic carbonates in moderate to high yields. Detailed investigation showed that the catalytic activity was highly affected by the counter anions of the ammonium salts; the iodides catalyzed efficiently the carbonate-forming reactions, whereas the bromide and chloride counterparts exhibited almost no catalysis. We also revealed that two important factors on the amine moieties that affected the catalytic reactions. First, the catalytic activity increased with increasing bulkiness of the substituents on the ammonium nitrogen atoms. Second, the catalysis became more efficient as the parent amines become more basic. Dicyclohexylammonium iodide was the best catalyst among the ammonium salts investigated in this study. As an application of this reaction system, we synthesized homo- and copolymers bearing epoxide pendant groups as substrates, which were converted with high efficiency into the corresponding homo- and copolymers bearing cyclic carbonate pendant groups under 1 atm at 45 °C. All polymers were easily purified simply by precipitation in water, and were isolated in high yields (>95%). 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013. Copyright
