ELECTRODEPOSITION OF TRANSPARENT CONDUCTIVE ZNO LAYER AS A NEW PROCESS FOR HIGH EFFICIENCY CIGS THIN FILM SOLAR CELLS

摘要

Electrodeposition of zinc oxide layers has been carried out in simple aqueous solutions at 80°C in two different electrolytes. An electrolyte containing only Zn(NO_3)_2 has been shown to produce very weakly doped layer (ND<10~(18) cm~(-3)). On the contrary the layer synthesized in a chlorine ions containing electrolyte presents a high free carrier concentration. During the growth, chlorine is incorporated in the ZnO lattice and act as doping agent in substitution of oxygen atoms (ClO). The physical properties (transparency, conductivity...) of this Cl-doped ZnO match well with those needed for PV front contact applications. CIGS based solar cells have been terminated with this layer with good success; high efficiencies up to 15.8% have been reached.