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

Abstract

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), H2O, and low toxicity triethylboron (TEB) instead of the commonly used highly toxic B2H6 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/cm2 illumination at 130 °C for 30 min. The details of this beneficial effect from HLS post-treatment for Cu(In,Ga)Se2 solar cells are also described together with the possible reason.