Study of the photo-adjustability of pn-junctions in photovoltaic mode coupled to photoconductors

Abstract

We propose a photo-adjustable arrangement that electrically combines a pn-junction operating in photovoltaic mode to a suitably designed photoconductor in order to keep the output current, voltage, or both, fixed. The characteristic I-V curves of a pn-junction under different light intensities do not intersect each other, resulting in different operational points for a given load. However, the resistivity of the photoconductor also changes with light, and by connecting it in parallel to the photovoltaic cell, and exposing both to the same level of irradiance, it is possible to find a design that alters the I-V curves of the cell in such a way that they will intersect at a chosen point. That could offer an alternative solution for a stable supply to autonomous DC loads. This paper presents an example case for a silicon pn-junction, considering the presence of parasitic components.