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Enhanced control of self-doping in halide perovskites for improved thermoelectric performance.

Tianjun LiuXiaoming ZhaoJianwei LiZilu LiuFabiola LiscioSilvia MilitaBob C SchroederOliver Fenwick
Published in: Nature communications (2019)
Metal halide perovskites have emerged as promising photovoltaic materials, but, despite ultralow thermal conductivity, progress on developing them for thermoelectrics has been limited. Here, we report the thermoelectric properties of all-inorganic tin based perovskites with enhanced air stability. Fine tuning the thermoelectric properties of the films is achieved by self-doping through the oxidation of tin (ΙΙ) to tin (ΙV) in a thin surface-layer that transfers charge to the bulk. This separates the doping defects from the transport region, enabling enhanced electrical conductivity. We show that this arises due to a chlorine-rich surface layer that acts simultaneously as the source of free charges and a sacrificial layer protecting the bulk from oxidation. Moreover, we achieve a figure-of-merit (ZT) of 0.14 ± 0.01 when chlorine-doping and degree of the oxidation are optimised in tandem.
Keyphrases
  • solar cells
  • perovskite solar cells
  • transition metal
  • hydrogen peroxide
  • drinking water
  • oxide nanoparticles
  • air pollution
  • nitric oxide
  • electron transfer
  • visible light
  • water soluble