Interpretation of ZnO luminescence peculiarities by use of rate equation system

Abstract

For the interpretation of ZnO luminescence and influence of surface plasmon resonance (SPR) on it a simplified approach is proposed. This approach is based on the set of rate equations (SRE), which describes processes taking part in luminescence. A number of experiments can be explained using this SRE, in particular, the proposed approach was applied for modeling experimental results for ZnO microstructure radiation intensity dependence on photoexcitation level and for consideration of insulating spacer role in ZnO/Ag system. In order to take into account visible emission, rate equations for level populations in band-gap and for corresponding photons and surface plasmons (SP) were added to SRE. By use of such SRE it is demonstrated that the form of visible luminescence intensity dependence on excitation level (P) like P1/3, as obtained elsewhere, is possible only if donor-acceptor pairs (DAP) exist. The proposed approach was also applied for consideration of experimental results on relation between UV and visible ZnO luminescence obtained in several works. This approach can be applied not only to ZnO-based structures but also to other semiconductors as well.