PHOTOPHYSICAL AND PHOTOCHEMICAL SYSTEMS WITH SEMICONDUCTORS FOR THE CONVERSION OF SOLAR ENERGY. A REVIEW

Abstract

Electrochemical energy sources are an alternative to replace technology based on the burning of fossil fuels. In an electrochemical system the potential drop spreads over a very narrow region at an interphase, creating high electric fields. So, there are good technological reasons to study semiconductor / electrolyte interphases. Currently, one of the ways to use renewable resources is through photovoltaic technology that directly converts solar radiation into electrical energy. This technology is manufactured from semiconductors, generally silicon, following an extremely careful and expensive manufacturing procedure. An option for photovoltaic devices is photoelectrochemical cells.These cells are made by the contact of a semiconductor electrode with a solution, which can be easily prepared and offers the possibility of low-cost manufacturing. Understanding how these devices work requires knowledge of the characteristics of semiconductors and how these materials behave in contact with an electrolytic solution and under illumination by sunlight. The present work describes, through an updated review, the principles and applications of semiconductor electrodes as the main components in a photoelectrochemical solar cell (PEC), to carry out chemical reactions of technological interest. In addition, the elements that are required for the improvement in the performance and construction of the PEC are discussed.