We demonstrate that the atomic structure dependent electron and optical properties of In2Se3 2D nanofilms are promising for application in photovoltaic-based devices. The In2Se3 nanolayers are constructed from vertically stacked semiconducting quintuple layers (QLs), which also exhibit spontaneous out of plane polarization (as well as in-plane polarization, not considered here). We investigated from first principles within Density Functional Theory (DFT), the impact of a different number of stacked QLs, and various combinations of out of plane polarization, either up () or down (), on the band gap in those layers, that can either render the stacked QL combination with a net or zero out of plane polarization. The band structure and dielectric response of the 2D In2Se3 nanomaterials were also modelled for a various number of stacked QLs with varying combinations of out of plane polarization of each individual QL layer within the stack.