Solar Cell Device Physics, 2nd Edition

Chapter Four

Homojunction Solar Cells

4.1 Introduction

We now begin our detailed examination of specific photovoltaic structures, and the first to be explored is the p–n and p–i–n homojunction solar cell class. The lineage of this solar cell type can be traced back to the work by Ohl1 in 1941 in which he demonstrated a grown Si p–n junction photovoltaic device. About 12 years later, a 6% efficient, diffusion-formed single-crystal Si p–n junction device was demonstrated2 and by 1958, 14% efficient single-crystal silicon devices were available using the diffused junction technology. While the Si cells continued to develop, efforts began on p–n homojunction cells based on other single-crystal semiconductor materials, such as GaAs.3 A shallow junction ...