Fabrication of p-type ZnO thin films via MOCVD method by using phosphorus as dopant source

Abstract

Phosphorus-doped p-type zinc oxide (ZnO) thin films have been deposited by metalorganic chemical vapor deposition without using additional thermal activation processes. In our experiment, diethylzinc (DEZ) was used as Zn precursor, and O 2 gas and P 2O 5 powder were used as oxidizing and phosphorus doping sources, respectively. We have reached a phosphorus content in the ZnO films of about 0.38 – 3.91 at%. The hole carrier concentration of the films varies from 2.01 × 1 0 17 to 1.61 × 1 0 18 cm - 3 , and mobilities are mainly in the range of 0.189 – 0.838 cm 2 V - 1 s - 1 . The lowest film resistivity achieved is 4.64 Ω cm. Energy-dispersive spectrometry (EDS) revealed that phosphorus has been successfully incorporated into the ZnO films. The p-type ZnO films possess high transmittance (90%) in the visible region. The growth parameters and phosphorus content both play significant roles in fabricating p-type ZnO films through phosphorus doping.