Determination of Electron Affinity of In2 O 3 from Its Heterojunction Photovoltaic Properties

In 2 O 3 ‐ Si , In 2 O 3 ‐ Ge , In 2 O 3 ‐ GaAs , and In 2 O 3 ‐ InP heterojunction solar cells have been fabricated and their photovoltaic properties have been investigated. All devices show rectifying and photovoltaic effects. The experimental results can be explained by a simple heterojunction energy band diagram. In order to match the experimentally observed polarities of the open‐circuit voltage and short‐circuit current of these heterojunction solar cells, the electron affinity of In 2 O 3 materials is determined to be 4.45 eV. The substrate‐resistivity dependence of open‐circuit voltage is consistent with the energy band diagram using the electron affinity value of 4.45 eV for In 2 O 3 .