DuPont™ Solamet® photovoltaic (PV) metallizations offer a comprehensive system of thick film materi­als used in the construction of both crystalline silicon and thin film photovoltaic (solar) cells. Solamet® offers advantages in efficiency and reliability, enabling more advanced and efficient solar cells to be constructed. The material properties and functional requirements of the front and the back sides of PV wafers dictate significant differences in the functionality of thick filmphotovoltaic metallization pastes.

n-type Silver Metallization

The front side is responsible for absorbing light and generating most of the electrical carriers.

Solamet® front side conductor features:

• Low contact resistance
• High conductivity
• Good line resolution
• Good solderability

p-type Aluminum Metallization

The function of the back-side conductor is to act as a sec­ond electrode in the cell.

Solamet® p-type Aluminum conductor features:

• Utilization of the back-surface field effect
• Efficient use of aluminum
• Low stress

p-type Silver Metallization

The function of the back side Silver or Silver-Aluminum conductor is to act as the interconnect part of the second electrode in the cell.

Solamet® back side Silver conductor features:

• Good ohmic contact
• Good solderability or weldability
• High paste coverage
• High soldered aged adhesion

Solamet® photovoltaic metallizations for Thin Film PV Cells

DuPont has now introduced afeatures a new range of low temperature screen printable pastes for all major thin film PV applica­tions enabling more cost effective manufacturing of solar cells with improved efficiency and yield.

The main purpose of the low temperature curing Ag Silver paste is for use as a front side current collector grid and bus bar to reduce the resistive losses due to the relatively low con­ductivity of the transparent conductive oxide (TCO) layer used in thin film PV devices.

DuPont™ Solamet® can be used on both rigid (glass, silicon) and flexible (polyimide, polyester, stainless steel) substrates.

Thin Film Applications

• Amorphous Silicon (a-Si/) / Microcrystalline Silicon (µuc-Si) - Ag Silver grid & bus bar
• Copper Indium Gallium Selenium (CIGS) - Ag Silver grid & bus bar
• Heterojunction - Ag Silver grid & bus bar
• Cadmium Telluride (CdTe) - Carbon ink (back contact)

For more information on our DuPont™ Solamet® photovoltaic metallizations view our Photovoltaic Metallizations Product Guide.