SiNx:Tb3+--Yb3+, an efficient down-conversion layer compatible with a silicon solar cell process

TL;DR

This study develops a SiN x : Tb 3+-Yb 3+ down-conversion layer via reactive magnetron co-sputtering, enhancing Yb 3+ emission for silicon solar cells by optimizing composition, microstructure, and processing conditions.

Contribution

It demonstrates a novel, compatible down-conversion layer with optimized fabrication parameters to improve silicon solar cell efficiency.

Findings

Optimized layer achieved highest Yb 3+ emission intensity.

Depositing at 200°C and annealing at 850°C yields comparable emission to higher temperature processes.

Reactive magnetron co-sputtering effectively incorporates rare earth ions into SiN x for down-conversion.

Abstract

SiN x : Tb 3+-Yb 3+, an efficient down-conversion layer compatible with silicon solar cell process Abstract Tb 3+-Yb 3+ co-doped SiN x down-conversion layers compatible with silicon Photovoltaic Technology were prepared by reactive magnetron co-sputtering. Efficient sensitization of Tb 3+ ions through a SiN x host matrix and cooperative energy transfer between Tb 3+ and Yb 3+ ions were evidenced as driving mechanisms of the down-conversion process. In this paper, the film composition and microstructure are investigated alongside their optical properties, with the aim of maximizing the rare earth ions incorporation and emission efficiency. An optimized layer achieving the highest Yb 3+ emission intensity was obtained by reactive magnetron co-sputtering in a nitride rich atmosphere for 1.2 W/cm${}^2$ and 0.15 W/cm${}^2$ power density applied on the Tb and Yb targets, respectively. It was determined that depositing at 200 {\textdegree}C and annealing at 850 {\textdegree}C leads to comparable Yb 3+ emission intensity than depositing at 500 {\textdegree}C and annealing at 600 {\textdegree}C, which is promising for applications toward silicon solar cells.