Atomic-layer deposited passivation schemes for c-Si solar cells

A review of recent developments in the field of passivation of c-Si surfaces is presented, with a particular focus on materials that can be prepared by atomic layer deposition (ALD). Besides Al2O3, various other novel passivation schemes have recently been developed, such as Ga2O3, Ta2O5, SiO2/Al2O3, HfO2/Al2O3 and TiO2, which altogether can passivate a wider variety of doped and textured Si surfaces. Moreover, they are interesting candidates in the emerging field of passivating contacts, for instance as novel tunnel oxides. In this field, ALD can offer some distinct advantages, such as a precise control in film thickness, composition and even area-selective deposition

Status and prospects for atomic layer deposited metal oxide thin films in passivating contacts for c-Si photovoltaics

In the field of photovoltaics, atomic layer deposition (ALD) is mostly known for its success in preparing Al2O3-based surface passivation layers for c-Si homojunction cells. In the last years, many novel types of c-Si heterojunctions have appeared, referred to as passivating contacts. In these concepts, metal oxide thin films are used for surface passivation, carrier selectivity and as transparent conductive oxide. This leads to the question whether the success of ALD for homojunctions can be translated into this new field as well. Therefore, this work provides an overview of these new concepts, and highlights both the current role and prospects of ALD in this field