Effects of post-deposition treatments on transparent conducting ZnO:B thin films grown by MOCVD

In this work, the effects of post-treatments such as air-annealing (AA), light soaking (LS), and heat-light soaking (HLS) on the electrical properties of boron-doped ZnO (ZnO:B) films were investigated. The ZnO:B films were deposited by metal organic chemical vapor deposition (MOCVD) using diethyl zinc (DEZ), H 2 O, and low toxicity triethylboron (TEB) instead of the commonly used highly toxic B 2 H 6 gas. Both the carrier concentration and electron mobility were increased after HLS post-treatment; thereby, the resistivity obviously decreased from 4.5 × 10 −3 to 2.4 × 10 −3 Ω·cm after HLS post-treatment under AM1.5, 100 mW/cm 2 illumination at 130 °C for 30 min. The details of this beneficial effect from HLS post-treatment for Cu(In,Ga)Se 2 solar cells are also described together with the possible reason.