高效能低維度鈣鈦礦材料應用於光電化學元件

In this thesis, we aimed to synthesize air-stable the electrochemically durable perovskite material via using the easily fabricated dye-sensitized solar cells as an appropriate evaluation platform. In Chapter 3, a steady, reliable, low-cost, and easily conducted fabrication platform for dye-sensitized solar cells was estabilished by using the commercial Ti-Nanoxide paste for transparent layer and the optimal TiO2 paste for light-scattering layer. Without synthesizing TiO2 nanoparticles and microparticles via using high temperature and pressure equipments, the uniform and reliable light-scattering TiO2 paste was prepared by adding 50 wt% of TiO2 solid, which was composted of Ti-Nanoxide/ST–41 (2/1 by weight), and poly(ethylene glycol) (PEG, 25 wt% with respect to the weight of ST–41) in a mixing solvent of tert-butyl alcohol/de-ionic water (9/1 by volume). Decent cell efficiency up to 8.47% was achieved, and the perovskite electrode exhibited good reproducibility and reliability for further studies of electro-catalytic properties. In Chapter 4, air-stable and electrochemical durable perovskite electrode of NF/TiO2/ FA(Pb1-xGex)I3 were successfully obtained by using 100% of formamidinium as the A-site molecule, doping 10% of germanium(II) iodide as the B-stie stabilizer, and adding tetra-alkyl-ammonium halides as the surface passivators. All the FA(Pb1-xGex)I3 perovskite films passivated by different tetra-alkylammonium halides exhibted good α–FAPbI3 crystalline phase, and maintained good thermodynamic stability without any crystal decomposition or decay in air for at least 4 months. Among tetra-alkylammonium surface passivators of different alkyl chain length (from ethyl (C2) to docyl (C12)), the tetra-n-hexylammonium (THA) iodide was found to provide the optimal cell performance. The bromide passivated on the FA(Pb1-xGex)I3 surface resulted in the formation of minor FAPbBr3 as extra electro-active sites for triggering I–/I3– redox reaction, while the chloride passivated on the FA(Pb1-xGex)I3 surface caused the decrease in electro-catalytic ability of FA(Pb1-xGex)I3 due to the self-aggregation of THA-Cl, inefficient surface passivation, and the blockade of the electro-active sites. The optimal NF/TiO2/FA(Pb1-xGex)I3/ THA-Br0.5I0.5 electrode exhibited good electrochemical durability and electro-catalytic ability toward multiple redox mediators (I–/I3–, CoII/III-phen, and CuI/II-dmp). The DSSC with the optimal NF/TiO2/ FA(Pb1-xGex)I3/THA-Br0.5I0.5 counter electrode reached 8.50% at 1 sun and 22% at 1 klux (Philips T5 lamp) in I–/I3– with good reproducibility; this cell effiency was 87% to that of the Pt-based DSSC (9.78%), showing a promising potential for the applications in various electrochmical systems.