Thyristor photovoltaic devices formed by epitaxial growth

Abstract

Typical commercial photovoltaic (PV) devices suffer from high rear surface recombination velocities that degrade performance and prevent economical gains through the use of thinner substrates. The triple-junction thyristor appears to provide an alternative structure that is simple to form and with the potential for improved performance through capitalizing on the excellent surface passivation achievable through the use of thermally oxidized n-type surfaces. When using phosphorus diffused p-type wafers, the additional rear p-type layer can be easily formed at low temperature by metal mediated epitaxial growth. These layers are studied and characterized to ascertain their suitability. Design considerations and strategies for the implementation of such layers into the thyristor structure for PV generation are presented and discussed. Thyristor PV devices have the additional advantage of blocking current in the dark, alleviating the need for blocking diodes.