What is CIGS?

 What is CIGS?

Copper Indium Gallium diSelenide (CIGS) technology is regarded by some as the most promising thin-film PV contender to the c-Si due to its high conversion efficiencies, potential cost effectiveness and incrementally improving manufacturability.

In order to stay successful and remain profitable, CIGS manufacturers must further increase the ratio of conversion efficiency to manufacturing cost of their modules. 

The former relies primarily on new technological advances, such as the advanced engineering solutions for the absorber layer, interface adjustment and use of better and purer materials. The latter is intimately related to the improved production throughput and yield, better material utilization and improved logistics.

GIGS Processing

GIGS 

In a typical CIGS device, fabrication starts with the deposition of a sputtered molybdenum (Mo) electrode on a substrate, such as soda-lime glass. The use of Mo as the back electrode has remained unchanged since the inception of the CIGS technology. In fact, molybdenum is one of the few metals that remain relatively inert during the CIGS high-temperature (>500 °C) selenization process. 

Despite the fact that CIGS manufacturing recipes vary significantly between individual module producers, the number of “knobs” available in tuning sputter-deposited Mo electrodes is always quite limited. Recipe differences include sputtering pressure and power, the levels of intentionally added impurities, compositional grading profile, and the number and position of sputtering targets in the coater, etc. All of these variables are crucial in achieving high conductivity, proper electrical matching to the CIGS, good adhesion and long-term stability.

The Mo electrode should be about 400-800 nm thick to achieve 0.2 – 0.5 Ohm/sq sheet resistance. Depending on the CIGS fabrication method, the back electrode represents 7-20% of the manufacturing cost of the complete module. There are a number of strong economical and technological reasons for CIGS companies to outsource the back Mo electrode from a large-scale glass manufacturer.

You can visit the following links for more information about  molybdenum or molybdenum alloy.

Molybdenum: http://www.molybdenum.com.cn/

Molytbdenum Alloy: http://www.molybdenum-alloy.com/