Highly surface-textured and conducting ZnO:Al films fabricated from oxygen-deficient target for Cu(In, Ga)Se2 solar cell application

Abstract

© 2014 Chinese Optics Letters Highly conducting ZnO:Al (AZO) films are normally prepared through substrate heating and post-annealing in reducing atmosphere, which is deleterious to maintain the high transparency of films and the overall solar cell performance. Here we fabricate AZO films through one-step sputtering at room temperature using oxygen-deficient targets prepared via double crucible method. The best-performed AZO film achieves a low resistivity of 4.4 × 10 -4 Ω cm, a high haze factor of 35.0%, and optimizes the efficiency of Cu (In, Ga)Se 2 solar cell with a high value of 14.15%. This letter demonstrates that oxygen deficiency can induce high surface texture, conductivity, and boost solar cell performance.