Textured ZnO Thin Films for Solar Cells Grown by a Two-step Process with the Atomic Layer Deposition Technique

B-doped ZnO films are prepared on Corning 7059 glass by atomic layer deposition (ALD) using diethylzinc (DEZn), H₂O as reactant gases, and diborane (B₂H₆) as a dopant gas. A two-step deposition process is introduced to grow textured and low-resistivity ZnO films by combining the ALD and conventional photo-induced metalorgainc chemical vapor deposition (photo-MOCVD) techniques. The electrical and optical properties of ZnO films are effectively improved by depositing lower-resistivity ALD-ZnO films on the textured photo-MOCVD-ZnO films while the textured surface morphologies are well maintained. Furthermore, the resistivity of the ALD-ZnO film was further improved by the two-step process and a low resistivity of 2.0×10^-4 Ω·cm was achieved for the film which was only about 400 nm thick.