The effect of the incorporation of Ti into ZnO nanoparticles on the responsivity of In/ZnO nanoparticles/In devices to solar irradiation is studied. The dependence of the sensitivity to solar irradiation, response time, grain size, luminescence and defects upon the addition of Ti is determined. The time-resolved photocurrent plot indicates that the rise and decay processes become faster when Ti is incorporated into ZnO nanoparticles. The ratio of photocurrent-to-dark current (i.e., photosensitivity) is about one order of magnitude for In/ZnO nanoparticles/In devices. However, the ratio of photocurrent-to-dark current is three-four orders of magnitude for In/TiZnO nanoparticles/In devices. An oxygen vacancy-related band model is proposed to describe the transition processes for free carrier generation. The incorporation of Ti into ZnO nanoparticles leads to the combined effect of a reduction in the grain size and the reduced number of oxygen vacancies, which serves to reduce the dark current and increase the value of photosensitivity.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering