Solar Cell Efficiency Improved by 0.8%

The Challenge

A PERC (Passivated Emitter and Rear Cell) solar cell manufacturer was pushing to increase cell conversion efficiency by narrowing front-side silver finger lines. Their existing silver paste used particles that were too coarse, causing:

• Minimum printable line width of 35 µm — wider than ideal for light capture
• High contact resistivity between silver fingers and the silicon emitter
• Excessive silver consumption per cell, driving up production costs

The Solution

LSBT supplied electrolytic dendritic silver powder with sub-micron particle size for front-contact paste formulation:

• D50 < 1 µm (ultra-fine grades down to <10 µm max size) enables screen-printed lines as narrow as 20 µm
• Ag 99.99% purity — minimizes impurity-related recombination losses at the Ag/Si interface
• Dendritic morphology — high surface area promotes sintering at lower firing temperatures
• Low apparent density (1.0-2.5 g/cm³) — improves paste rheology and print resolution

The Results

The reformulated front-contact paste using LSBT's sub-micron dendritic silver enabled finger width reduction from 35 µm to 20 µm, increasing the light-active area of each cell. Absolute conversion efficiency improved from 22.5% to 23.3%. Silver paste consumption per cell decreased by 15% due to finer line geometry.