J. Parisi et al., QUANTUM EFFICIENCY AND ADMITTANCE SPECTROSCOPY ON CU(IN,GA)SE-2 SOLAR-CELLS, Solar energy materials and solar cells, 50(1-4), 1998, pp. 79-85
We investigate the electronic transport properties of Cu(In,Ga)Se-2 so
lar cells by means of quantum efficiency and temperature dependent adm
ittance spectroscopy. A simple evaluation scheme of quantum efficiency
data is introduced which accounts for recombinatoric losses in the Cd
S buffer layer and in the Cu(In,Ga)Se-2 absorber. By admittance spectr
oscopy, we find that the controlled incorporation of Na into the absor
ber material leads to a shallow acceptor state at about 75 meV above t
he valence band.