Electron beam irradiation of sputtered Cu–In–Se precursors with double layered structure

Cu–In–Se double-layered precursors were prepared using DC- and RF-sputtering methods and then irradiated with an in-situ electron beam irradiation unit. The irradiation time, electron dose and intensity were kept constant at 300 s, 200 W of RF power and 2.5 kV of DC power, respectively. The thicknesses of all e-beam irradiated CuInSe2 films were decreased from 850 nm to 700 nm and better adhesion between interfaces was observed in the Cu2Se/In2Se3 structure. The crystalline properties of e-beam irradiated CuInSe2 films were clearly shown in the In2Se3/Cu2Se structure formed at 5 mTorr with the Se/(Cu+In) composition ratios of 1.24 and 1.22, applicable to the solar cell. A CuInSe2 solar cell was fabricated, and its conversion efficiency was 6.82%, with 390 mV of open circuit voltage, 32.3 mA/cm2 of short circuit current density and 54% fill factor. E-beam irradiation onto Cu–In–Se precursors could be a good candidate for preparation of CuInSe2 films.

► Prepared CuInSe2 films by e-beam irradiation of sputtered Cu–In–Se precursors.
► Irradiation only for 300 s without supply of selenium.
► Better adhesion between interfaces is observed in the Cu2Se/In2Se3 structure.
► We prepare excellent crystalline properties of the CuInSe2 absorber film.
► We report fabrication of e-beam irradiated device with 6.82% efficiency for the first time.