Low-resistivity, stable p-type ZnO thin films realized using a Li–N dual-acceptor doping method

Abstract

A Li–N dual-acceptor doping method has been developed to prepare p-type ZnO thin films by pulsed laser deposition. The lowest room-temperature resistivity is found to be ∼0.93Ωcm, much lower than that of Li or N monodoped ZnO films. The p-type conductivity of ZnO:(Li,N) films is very reproducible and stable, with acceptable crystal quality. The acceptor activation energy in ZnO:(Li,N) is about 95meV. ZnO-based homostructural p-n junctions were fabricated by depositing an n-type ZnO:Al layer on a p-type ZnO:(Li,N) layer, confirmed by secondary ion mass spectroscopy. The current-voltage characteristics exhibit their inherent rectifying behaviors.

Influence of post-annealing time on properties of ZnO: (Li, N) thin films prepared by ion beam enhanced deposition method

“…ZnO: (Li, N) film annealed for 30 min shows a hole concentration of 3.72 9 10 17 cm -3 , hole mobility of 1.82 cm 2 /V s, and resistivity of 10.83 X cm. Compared to other preparation methods, the electrical properties of ZnO: (Li, N) film prepared by IBED are superior to that by RF-magnetron sputtering method [22,23] and plasma-assisted molecular beam epitaxy [24], but inferior to that by pulsed laser deposition method [11,25]. We may draw the conclusion from what has been discussed above: appropriate annealing can eliminate the sputtering damage and improve the crystal quality, and help lithium to incorporate in ZnO lattice and realize the substitutional action.…”

ZnO Doping and Defect Engineering—A Review

“…And most importantly, the p-type conduction lasts over a year, which is far better than monodoping. The improved stability of dual acceptor doping indicates that the formation of compensating defects can be reduced with dual acceptor codoping [155]. XPS data have shown that Li and N are possibly combined to form a Li-N complex with a shallow acceptor level of 126 meV [153].…”

The ZnO p-n homojunctions modulated by ZnMgO barriers

“…Compared the Q 1 and Q 2 with H2, the Q series have voltage regulator diode rectification property which is different with the same type ZnO p-n junctions (650nm) 18 which is much thicker than our Q series. Therefore the I-V rectification property in the thinner p-n homojunctions could be enhanced and modulated by embed Zn 0.85 Mg 0.15 O ADB structure.…”