Photovoltaic cell and module efficiency as drivers of innovation in photovoltaic technology

Ladislava Černá and Vítězslav Benda

Abstract

Since the beginning of the use of photovoltaics for electricity generation, the efficiency of photovoltaic modules has been one of the most important parameters. During development, a thorough analysis of physical processes is performed, while various modifications of photovoltaic cells are designed with the aim of reducing optical, recombination and electrical losses and achieving maximum cell efficiency using affordable materials and technologies. This paper discusses the design principles, critical technological operations and the resulting efficiency development of crystalline silicon cells and modules. Individual design solutions such as aluminum back surface field, passivated emitter and rear cell, tunnel oxide passivated contact, heterojunction technology, and back contacted are discussed, including their physical and practical efficiency limits. The paper also investigates the economic impact of increasing the efficiency of photovoltaic modules. While increasing efficiency leads to a reduction in area-related costs, the technological improvements leading to an increase in efficiency result in an increase in production prices. Therefore, a positive economic effect can be seen, especially in systems with a large share of area-proportional costs.