Abstract
We examined the ultrafast dynamics of photocarriers in nanocrystalline ZnOxNy thin films as a function of compositional variation using femtosecond differential transmittance spectroscopy. The relaxation dynamics of photogenerated carriers and electronic structures are strongly dependent on nitrogen concentration. Photocarriers of ZnOxN y films relax on two different time scales. Ultrafast relaxation over several picoseconds is observed for all chemical compositions. However, ZnO and oxygen-rich phases show slow relaxation (longer than several nanoseconds), whereas photocarriers of films with high nitrogen concentrations relax completely on subnanosecond time scales. These relaxation features may provide a persistent photocurrent-free and prompt photoresponsivity for ZnO xNy with high nitrogen concentrations, as opposed to ZnO for display applications.
Original language | English |
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Pages (from-to) | 5062-5065 |
Number of pages | 4 |
Journal | Optics Letters |
Volume | 39 |
Issue number | 17 |
DOIs | |
State | Published - 2014 |