Progress Of Research On The Visible Luminescence Mechanism Of ZnO

ZnO is a kind of direct wide-gap semiconductor, which has hexagonal wurtzite crystal structure and opto-electronic and piezoelectric characteristics. At room temperature,its band gap is 3.37 eV, exciton binding energy may reach 60 meV, ensuring its intense excitonic luminescence. Moreover, in virtue of the excellent opto-electronic characteristics, ZnO is promising for applications in the fields of LED, UV detector, gas sensor and flat plate display, etc.Commonly, the luminescence of ZnO includes near band edge (NBE) UV emission and deep level (DL) related visible emission. Although the visible luminescence mechanism of ZnO is of great importance in ZnO research, and has been intensively investigated by many groups, using methods such as quantum confinement, band edge modulation and surface modification, etc., no unambiguous conclusion has been reached up to now because of its complicated characteristics. In this thesis, the research progress on the visible luminescence of ZnO materials was reviewed in detail.