An Experimental Study on Step-Up DC–DC Converters for Organic Photovoltaic Cells

Abstract

This work studies two circuit topologies to step-up the voltage supplied by an organic photovoltaic (OPV) cell. Comparison and validation of the proposed topologies are accomplished throughout analytical, simulation, and experimental results. Two circuit solutions were found more suitable to boost the harvested OPV cell low voltage, depending on the load condition: the classical hard-switching boost converter and a multilevel boost converter. Both experimental circuits include the drive of the MOSFET switch based on an LC oscillator at 1.2 MHz, allowing the implementation of a conversion system, supplied by voltages as low as 500 mV, with output voltages from 1.2 V up to 7 V, under solar simulator conditions. The circuit area for each converter prototype is 2.35 cm2, with a total area below 3.0 cm2 for the overall energy harvesting system, including the OPV cell, which makes this proposal an extremely compact solution for ultra-low power harvesting applications.