Electron Beam Irradiated Al Doped ZnO Thin Films as Efficient Tunnel Recombination Junction for Hydrogenated Amorphous Silicon/Cu(In,Ga)Se₂ Tandem Solar Cells.

A tunnel recombination junction (TRJ) layer for hydrogenated amorphous silicon (a-Si:H)/ Cu(In,Ga)Se₂ (CIGS) tandem solar cells is investigated. An Al-doped zinc oxide (AZO) thin film is applied to the TRJ, and the influence of electron beam (e-beam) irradiation on defects along the TRJ is investigated. The AZO thin films are prepared using radio frequency (RF) sputtering and the e-beam is irradiated at 200 W RF power and 2 keV DC power for 5 min. In the e-beam irradiated AZO thin film, the number of oxygen vacancies and Zn interstitials increases, which in turn strengthens the effect of defect-enhanced tunnel recombination.