High short-circuit current density in a non-toxic Bi2S3 quantum dot sensitized solar cell

A high short-circuit current density, J(sc), with an average of 20 mA/cm(2) has been obtained in a quantum dot-sensitized solar cell (QDSSC) assembled with non-toxic Bi2S3 quantum dots (QDs) as the unique sensitizer material. High-density sensitization of the fluorine-doped tin oxide/c-TiO2/m-TiO2/s-TiO2 heterojunction with Bi2S3 QDs has been achieved by the addition of 1,2,3-propanetriol as a complexing agent of bismuth ions. The atomic percentage concentration of Bi and S in the heterojunction increased by 11.40 and 19.64 times with respect to the non-use of the complexing agent, respectively. The Successive Ionic Layer Adsorption and Reaction method without the use of 1,2,3-propanetriol generates a J(sc) of 0.71 mA/cm(2), whereas the addition of the complexing agent produces a J(sc) of 15.98 mA/cm(2), which means an increase of 22.5 times, and an additional thermal treatment of the Bi2S3 QDs increases the Jsc to a maximum of 21 mA/cm(2). The proposed Bi2S3 QDs preparation methodology can be used for the fabrication of other solar device configurations based on Bi2S3 as a non-toxic photovoltaic material, unlike the toxic chalcogenide semiconductors containing lead and cadmium. (C) 2021 Elsevier Ltd. All rights reserved.