Zn-alloyed MAPbBr3 crystals with improved thermoelectric and photocatalytic properties

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.