R. Scheer et al., DETERMINATION OF CHARGE-CARRIER COLLECTING REGIONS IN CHALCOPYRITE HETEROJUNCTION SOLAR-CELLS BY ELECTRON-BEAM-INDUCED CURRENT MEASUREMENTS, Solar energy materials and solar cells, 49(1-4), 1997, pp. 299-309
The depth-dependent experimental collection functions F(z) of solar ce
lls with CuInS2, CuGaSe2 and CuInSe2 absorber layers are derived from
planar electron-beam-induced current (EBIC) measurements. It is shown
that F(z) for CuInS2 and CuGaSe2 cells can be interpreted by a simple
heterojunction model. For CuInSe2 cells, however, a near-interface reg
ion with modified experimental collection function is found, which is
possibly due to an ordered vacancy compound formed at the surface. Mor
eover, high values of F(z) for minority carriers generated near the ba
ckcontact of the CuInSe2 cell are indicated. This can be interpreted b
y either the implementation of a backsurface field in these devices or
perpendicular junctions at grain boundaries.