Senior Research Fellow
Stion Corporation, California, United States

New emitters for CIGS: from cells to full size modules

In this talk we will describe our research efforts leading to the development of Zn(O,S) based p-n junctions for CIGSSe cells and modules. The exploratory cell level development work was done in collaboration with NREL where CBD and Sputtering based emitter layers and cells were developed. The CBD Zn(O,S) process was adapted to production and a certified champion module was achieved. The sputtering approach also produced efficient cells when the film composition and thickness were tuned. Finally, we have achieved superior performance for full size modules utilizing ALD Zn(O,S) buffer layers. Output power increased by 5 to 7W compared to the baseline CdS modules. In this talk, we will discuss the scientific underpinnings of the above results, the opportunities for further improvements and the cost comparisons. 


Dr. Kannan Ramanathan is a Senior Research Fellow at Stion Corporation in California, a manufacturer of high efficiency chalcopyrite based thin film PV products. Kannan has over 30 years of experience in NREL and industry and he has worked on CIGS and CdTe solar cells. He has made record cells at NREL and performed work on junction interfaces that is widely followed. Kannan is engaged in process research that is likely to yield higher efficiencies at much reduced cost. This is his second visit to Singapore and he is greatly impressed by the work of SERIS and other institutions.