Thanks to recent advancements in nanofabrication and 2 3D packaging, typical Internet of Things (IoT) devices can now be 3 wirelessly controlled using millimeter scale sensors known as 4 Internet of Tiny Things (IoT²) devices. Since these low power devices 5 may be exposed to low and indirect solar irradiation, we demonstrate 6 a novel meso-superstructured solar cell (MSSC) that allows low flux 7 light to be harvested from both its top and bottom sides. Our cell is 8 based on either a dye-sensitized solar cell (DSSC) or a perovskite 9 solar cell (PSC). The active layer in the proposed MSSCs was tuned 10 to allow semi-transparent behavior. Moreover, we developed an 11 experimentally validated model that enables optimization of the 12 active layer thickness for different semi-transparent MSSC 13 applications. In MSSCs, such optimization is necessary to balance 14 the trade-off between transparency and efficiency for various active 15 layer thicknesses. Fabricated DSSCs and PSCs cells were used to 16 validate the simulation results. The fabricated DSSC achieved a 17 harvesting ratio of 1:10 with a conversion efficiency of around 2% at 18 one Sun. We demonstrate that the optimum thickness of the 19 mesoporous TiO2 active layer in DSSCs was 800 nm, enabling a 20 maximum power density of 7 mW/cm 2 .