Zn-alloyed MAPbBr3 crystals with improved thermoelectric and photocatalytic properties

Abstract

The B-site doping of organic–inorganic lead halide perovskites of the form MAPbX₃ is not only an effective way to improve energy conversion (solar-electrical, thermal-electrical, solar-chemical, etc.) performance, but it is also eco-friendly, reducing the toxic Pb content. To the best of our knowledge, there are few reports on the photocatalytic and thermoelectric properties after the partial doping of Zn²⁺ into the Pb²⁺ lattice sites of perovskite MAPbBr₃ crystals fabricated through a solvothermal route (Zn–MAPbBr₃). Systematic characterization, including XRD, EDS, XPS, UV-vis, PL, N₂ adsorption/desorption, Hall measurement, time-resolved photoluminescence measurement (TRPL), and electrochemical analysis, showed that the smaller Zn²⁺ guests increase the Goldschmidt tolerance and octahedral tilting factor of MAPbBr₃ and enhance the carrier concentration, carrier mobility and conductivity, active site number, and oxidation abilities of Zn–MAPbBr₃. Finally, Zn–MAPbBr₃ crystals exhibited an improved absorption capacity and better photocatalytic degradation performance toward RhB dye and improved thermoelectric transportation properties, including better electrical conductivity and a more positive Seebeck coefficient, compared with pristine MAPbBr₃.