Combining electrochemistry with optical spectroscopy to measure changes in the absorption in different redox environments is a powerful tool to determine the electronic structure of semiconductor quantum dots (QDs) . Notable examples for colloidal QDs involve CdSe , ZnO 8 , CdTe 9, 10 , MoS 2 , CsPbBr 3 , CuInS 2 , Cu (1-x) S , PbS , and PbSe , where spectroelectrochemistry has been applied to detect the positions of their band edges or energy levels. Since spectroelectrochemistry requires an optically transparent and conductive working electrode, the study of IR-active QDs, such as PbS, poses an additional challenge, which is typically met by utilizing transparent conductive oxides (TCOs), such as indium oxide. The required high conductivity and high transmittance for infrared photons with reduced plasmon oscillations can be achieved by fine-tuning the carrier density in In 2 O 3 through fluorine or tin dopants. An underexplored dopant in this context is hydrogen, which can be incorporated at interstitial or substitutional sites to form shallow donor states in the In 2 O 3 to increase the carrier concentration at the cost of a relatively small scattering cross-section compared to F:-or Sn:TCOs .