CUINS2 WITH LAMELLAR MORPHOLOGY .2. PHOTOELECTROCHEMICAL BEHAVIOR OF HETEROGENEOUS MATERIAL

Lamellar CuInS2 material grown in a steep temperature gradient shows h eterogeneous composition and complex photoeffects. Besides predominant n-type behavior, the electrode surface has areas with intrinsic or p- type conductivity, the latter usually corresponding to indium-rich reg ions. An inverted (cathodic) photocurrent is observed at n-type electr odes polarized under accumulation conditions. Both spectral dependence , with a pronounced peak for energies around the bandgap, and quantum yields >1 suggest that these photoeffects originate from photoconducti vity phenomena in the crystal bulk. Variability in electronic properti es limits the average performance of the material in solar cells.