Reproducible growth of p-type ZnO:N using a modified atomic layer deposition process combined with dark annealing

Nitrogen doped ZnO (ZnO:N) films were deposited by atmospheric atomic layer deposition (ALD) between 100 and 300°C. Postannealing was required to remove compensating defects. After a low temperature dark annealing, originally n-type films became p-type. Films deposited at low temperatures (⩽150°C) have low hole mobilities (μ) of 0.2–0.4cm2V−1s−1 and moderate hole concentrations (np) of around 1×1015cm−3. Higher temperature deposited films (⩾200°C) have higher μ values (6cm2V−1s−1) but np values <1×1013cm−3. This crossover in transport properties can be explained by the opposing effects of deposition temperature on nitrogen doping level and distribution, and film crystallinity.