# Optimizing Rheology and Structure of Silver Pastes for Screen-Printed Silicon Solar Cells

## TL;DR

This paper explores how the composition of silver pastes affects their performance in solar cells, aiming to improve efficiency and reliability.

## Contribution

The study introduces a novel optimized formulation of silver paste with specific ratios of solvents and additives for enhanced performance.

## Key findings

- The optimized paste achieved a height-to-width ratio of 0.35 and a sheet resistance of 1.43 Ω/□.
- The study established direct relationships between organic vehicle composition and paste rheology.
- The formulation provides practical guidance for designing high-performance conductive pastes for solar cells.

## Abstract

Solar energy, as a clean and renewable resource, plays a pivotal role in advancing sustainable energy technologies. The efficiency of front-side silver paste is critical for the photovoltaic performance of Tunnel Oxide Passivated Contact (TOPCon) solar cells. In this study, we comprehensively investigated how the composition of organic vehicles in conductive pastes influences both printing rheological properties and electrical performance. Through rheological characterization, contact angle measurements, and Three-Interval Thixotropy Tests (3ITT), we examined the effects of varying solvent, binder, and thixotropic agent ratios on paste properties. The optimized formulation—a solvent mixture of lauryl alcohol ester (TE), butyl carbitol (DGME), butyl carbitol acetate (BCA), and dibutyl phthalate (DBP) in a 3:4:2:1 ratio, with ethyl cellulose (EC) STD10 as the binder and a polyamide wax (PAW)–hydrogenated castor oil (HCO) thixotropic agent at a 3:1 mass ratio—demonstrated superior viscosity control and rapid structural recovery. Printed grid lines achieved a height-to-width ratio (H/W) of 0.35 and a sheet resistance (Rs) of 1.43 Ω/□. These findings reveal direct relationships between organic vehicle composition, paste rheology, and functional performance, providing practical guidance for the design and optimization of high-performance conductive pastes for c-Si solar cells. This work establishes a foundation for improving both the efficiency and reliability of next-generation silver paste formulations in photovoltaic applications.