Heterojunction CuO@ZnO microcubes for superior p-type gas sensor application

CuO@ZnO core-shell cubes with controlled shell thickness were synthesized using a facile and environment-benign two-step solution route. A bending behavior was observed when electrical testing was conducted on the CuO@ZnO core-shell heterostructure coating, demonstrating formation of heterojunction barrier. Moreover, the CuO@ZnO appears to be a superior material for p-type sensor applications, it offers 2.6 times higher response, faster recovery rate and better selectivity comparing to the pristine CuO sensor. The enhanced gas sensing performance can be attributed to the coating of ZnO shell and improvement of the effectively electrical contacts between heterojunction materials.