Exploring Na Doping in ZnO Thin Films: Electrical and Optical Insights

Abstract

Strategies to achieve p-type behavior in semiconductor oxides are an important current topic of research. Our study showed that sodium-doped zinc oxide thin films are a plausible approach. The insertion of dopant allowed a transition between n-type p-type electrical behavior in specific temperature ranges around 300 K. Annealing procedures under controlled atmospheres, including Ar, N2, and O2, increased the hole density up to a magnitude of 1016 cm−3, although this also reduced the window temperature. The micro-photoluminescence spectra showed an enhancement of defect-related emissions as the dopant content increased. Notably, yellow-green emissions (around 2.38 eV–520 nm) were the most prominent in the as-grown samples. After annealing, a strong redshift of the defect band was observed (around 1.85 eV–670 nm). Our findings showed that p-type ZnO:Na films exhibited emissions associated with RGB primary colors. In a chromaticity diagram, as-grown samples appeared near the white range, annealed films were close to the warm white area, and O2 annealed films trended within the red range.

Long Electrical Stability on Dual Acceptor P-Type ZnO:Ag,N Thin Films

“…This behavior due to hydrogen tends to diffuse very easily in large quantities into the structure of ZnO, and in turn, it is present in all the techniques used for the 2 deposition of ZnO thin films. Despite the extensive amount of work reported on p-type thin films deposited by different techniques and with different doping elements, which may enter in substitution of oxygen or zinc, a reliable electrical conductivity for p-type ZnO has not yet been achieved [6][7][8][9][10].…”

Long Electrical Stability on Dual Acceptor p-Type ZnO:Ag,N Thin Films

“…This behavior is due to hydrogen tends to diffuse very easily in large quantities into the structure of ZnO, and in turn, it is present in all the techniques used for the deposition of ZnO thin films. Despite the extensive amount of work reported on p-type thin films deposited by different techniques and with different doping elements, which may enter into the substitution of oxygen or zinc, a reliable electrical conductivity for p-type ZnO has not yet been achieved [ 6 , 7 , 8 , 9 , 10 ].…”