Crystalline Silicon Solar Module for Portable Applications

A photovoltaic (PV) microsystem based on a 4-cell solar module, with solar cells fabricated in-house, is presented in this paper. Each cell provides an open circuit voltage of $1.03V$ and a short circuit current of $48.5mA$. The system is capable of providing an output current of $3mA$ at the constant output voltage of $3.3V$. The DC-DC conversion relies on a step-up converter LM2621 from Texas Instruments. The experimentally obtained V-I and P-I curves show the capability of the module to charge a battery of $3mAh$ capacity.