Atomic layer deposition for photovoltaics

Photovoltaic (PV) conversion is an essential component of the energy mix, and is enjoying very strong growth thanks to cost reductions combined with support policies and technological advances. This article analyzes the contribution of Atomic Layer Deposition (ALD) to solar cell technologies.

ALD is a chemical vapor deposition technique that enables the growth of inorganic materials in ultra-thin, uniform, conformal layers of sub-nanometer thickness. Based on the sequential introduction of precursors, it involves surface chemical reactions and self-limiting saturation mechanisms that enable materials engineering on an atomic scale.

The applications of ALD for PV are diverse, with varying degrees of maturity: from the passivation of industrial-type silicon cells to innovative new architectures. This article presents the main uses of ALD for PV, and discusses the strengths and limitations of the process in a field where any innovation must satisfy the constraints of cost, size and stability over time.

Note: at the end of the article, readers will find a table of acronyms, notations and symbols used throughout the article.