New research findings: Enhanced efficiency of CIGS cells with MoNa sputtering targets.

Small quantities of sodium in the CIGS absorber improve the efficiency of a CIGS cell. Research findings from the Helmholtz-Zentrum Berlin (HZB) confirm that MoNa sputtering targets are particularly suitable as a sodium source for CIGS thin-film solar cells.

MoNa-Sputtertarget

The use of sputtering targets made from molybdenum-sodium (MoNa) allows CIGS manufacturers to achieve a homogeneous distribution of sodium and precisely control the sodium content. The Helmholtz-Zentrum Berlin recently investigated various different rear contact designs in the reactive magnetron sputtering process for CIGS absorber layers.
Alongside an NaF doping layer, the HZB team led by Dr. Klaus Ellmer also used a 270-nm MoNa layer. When the MoNa layer was used, a significantly reduced loss of indium was observed while maintaining comparably high levels of cell efficiency.
The detailed findings of the research by the Helmholtz-Zentrum Berlin have been published in:

Reactive magnetron co-sputtering of Cu(In,Ga)Se2 absorber layers by a 2-stage process: Role of substrate type and Na-doping. Jonas Schulte, Karsten Harbauer, Klaus Ellmer, Thin Solid Films, 2015, Vol. 582, 95-99.
http://www.sciencedirect.com/science/article/pii/S0040609014010682

Plansee is able to supply a range of different MoNa sputtering targets with differing sodium content for sodium doping of CIGS solar cells. MoNa targets are available as planar targets or as rotary targets for even higher material utilization. Read more about MoNa sputtering targets from Plansee.