Photovoltaic-Generated Millivolt Reference Using Multiple Integrated Photovoltaic Cells

This study presents a novel voltage reference topology designed through a self-generated millivolt reference obtained from multiple on-chip integrated photovoltaic cells. The difference in the open-circuit voltage ( VOC ) between two photovoltaic cells (Δ VOC ) is used as the voltage reference. A heavily-doped region is formed at the silicon/contact interface, which serves as the electrical passivation that changes the order of the surface recombination velocity from 10 6 - 10 7 cm/s to 10 2 cm/s. Therefore, one electrically passivated cell and one un-passivated cell are used in the proposed voltage reference topology. Utilizing the two cells results in the generation of illuminance-independent Δ VOC , which is temperature dependent. Consequently, including an additional VOC with the coefficient (α VOC ) successfully eliminates the temperature-dependency and satisfies the voltage-reference demands. Numerical simulation analysis demonstrates that an area of < 0.001 mm 2 is available in the two cells topology, and a total area of 0.0014 mm 2 is required to eliminate temperature variations in the three cells topology.