Source: Intech Technologies

Exploring Edge Defined Film Fed Growth (EFG) Technique in Photovoltaics

Introduction

The photovoltaic market heavily relies on the production of silicon wafers, typically obtained by slicing large silicon ingots. However, there are alternative techniques that aim to grow wafers directly, eliminating the need for cutting processes.

Edge Defined Film Fed Growth (EFG) Technique

The Edge Defined Film Fed Growth (EFG) technique is a method used to grow silicon sheets with controlled thickness. A graphite die is employed to define the sheet’s thickness, leading to the crystallization of silicon with large grains. By carefully adjusting the temperature profile of the die, the silicon sheets form with desired characteristics.

Implementation

In its simplest form, the EFG technique results in the production of a large cylindrical material. Traditionally, these cylinders were in polygon shapes, but recent advancements have introduced the use of large cylindrical shapes. The curved material obtained from the cylinders is later flattened during subsequent processes such as cell stringing and encapsulation.

By utilizing the EFG technique, manufacturers can produce silicon wafers with specific thickness and grain structures, offering an alternative to the conventional method of slicing ingots. This technique provides more flexibility in wafer production and can lead to enhanced efficiency in the overall photovoltaic manufacturing process.

Source: Ferrotec Global