Changes in hydrogen concentration and defect state density at the poly-Si/SiO_x/c-Si interface due to firing

authored by

Christina Hollemann, Nils Folchert, Steven P. Harvey, Paul Stradins, David L. Young, Caroline Lima Salles de Souza, Michael Rienäcker, Felix Haase, Rolf Brendel, Robby Peibst

Abstract

We determined the density of defect states of poly-Si/SiO_x/c-Si junctions featuring a wet chemical interfacial oxide from lifetime measurements using the MarcoPOLO model to calculate recombination and contact resistance in poly-Si/SiO_x/c-Si-junctions. In samples that did not receive any hydrogen treatment, the D_it,cSi is about 2 × 10¹² cm⁻² eV⁻¹ before firing and rises to 3–7 × 10¹² cm⁻² eV⁻¹ during firing at measured peak temperatures between 620 °C and 863 °C. To address the question of why AlO_x/SiN_y stacks in contrast to pure SiN_y layers for hydrogenation during firing provides better passivation quality, we have measured the hydrogen concentrations at the poly-Si/SiO_x/c-Si interface as a function of AlO_x layer thickness and compared these to J₀ and calculated D_it,c-Si values. We observe an increase of the hydrogen concentration at the SiO_x/c-Si interface upon firing as a function of the firing temperature that exceeds the defect concentrations at the interface several times. However, the AlO_x layer thickness appears to cause an increase in hydrogen concentration at the SiO_x/c-Si interface in these samples rather than exhibiting a hydrogen blocking property.

Organisation(s)

Laboratory of Nano and Quantum Engineering
Solar Energy Section
Institute of Electronic Materials and Devices

External Organisation(s)

Institute for Solar Energy Research (ISFH)
National Renewable Energy Laboratory
Colorado School of Mines (CSM)

Type

Article

Journal

Solar Energy Materials and Solar Cells

Volume

231

ISSN

0927-0248

Publication date

10.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Surfaces, Coatings and Films

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1016/j.solmat.2021.111297 (Access: Open)