centrotherm to offer selective emitter process upgrade with 17.1% average cell efficiency

Following its evolutionary approach to c-Si cell conversion efficiency enhancements via its ‘FlexLine’ turnkey production line offering, centrotherm photovoltaics has reported 17.1% average efficiency on customer supplied multi-crystalline material using selective emitter process technology. centrotherm already guarantees production efficiencies of 16.6% for the mass production of multi-crystalline cells using the "FlexLine Plus" turnkey production line.

centrotherm reiterated that it is pursuing an R&D roadmap that should achieve annual efficiency enhancement of 0.5% in mono- crystalline cells and 0.4% in the multi-crystalline cells. However, the company noted that it was already ahead of its roadmap for 2009.

"An efficiency enhancement of 0.5 percent allows production costs to be cut by around 3 percent," was how Dr. Peter Fath, CTO of centrotherm photovoltaics, summed up the significance of this goal. "This allows us to continuously realize cost-saving potentials for our customers that strengthen their competitiveness."

Selective emitter technology is one of first steps many PV manufacturers are employing to boost cell efficiencies as the process can be injected into existing lines relatively easy and does not disrupt the conventional process flow.

The selective emitter technology significantly diminishes this absorption loss applying a high phosphorus concentration only to a partial area where it is actually required.

Importantly, selective emitter technology is a relatively low cost process, enabling manufacturers to continue to reduce production costs while boosting cell efficiencies.

Centrotherm said it would offer upgrade options for existing turnkey production lines to incorporate the selective emitter technology.

The company also highlighted that it was developing a new mono-crystalline back side cell process enhancement that have so far achieved best values of 18.6% without the use of selective emitter enhancements.

"Using selective emitters and further retrofitting packages, we are achieving efficiency enhancements for crystalline solar cells that hold potential for the mass production of high-efficiency cells,” added Dr. Fath.