Planar rose-like ZnO/honeycombed gallium nitride heterojunction prepared by CVD towards enhanced H2 sensing without precious metal modification

In this work, through chemical vapor deposition (CVD) method, almost indistinguishable planar rose-like ZnO (PRZ) nanostructures could be prepared on the surface of honeycombed gallium nitride (HGaN) after more than ten deposition tests, and then constructed into PRZ/HGaN heterojunction gas sensor. Subsequent gas behaviors showed that the PRZ/HGaN heterostructure constructed by CVD greatly improved the selectivity and response value (32.5 at 100 ppm) to H2, and realized the improvement of the H2 sensing performance without noble metal modification. Importantly, fast response and recovery time was 47 s and 6 s, respectively. Meanwhile, this sensor presented excellent selectivity and stability. Ultimately, the dynamic monitoring of the sensor was performed for five consecutive months, and the fluctuation ratio of the response value (sensitivity) did not exceed +/- 2%. It could be predicted that the as-obtained sensor was expected to promote the substantial process of industrialization of highly stable metal oxide/HGaN heterojunction sensors.

Automated summary

In this study, a PRZ/HGaN heterojunction gas sensor was successfully prepared using CVD method, demonstrating improved selectivity and response value to H2. The sensor showed fast response and recovery time, as well as excellent stability and selectivity. Monitoring for five months showed minimal fluctuation in response value, indicating the potential for industrialization of stable metal oxide/HGaN heterojunction sensors.