Zno-based Low-dimensional Materials And Their Application In Photodetectors And Solar Cells

ZnO-based semiconductors are a kind of wide-gap materials, which are intentionally investigated. They are of very important significance for study, either in short-wavelength emitting devices or in detectors. ZnO-based low-dimensional materials and structures, especially, have a lot of unique energy-band properties and electric and optical characteristics. The achievements of the dissertation are as follows:1.MgZnO films with excellent surface properties are prepared on a glass substrate by the sol-gel technique. The absorption spectrum measurement showed that the gap of the material was with in 3.25-3.45eV which means that the material made possession of excellent properties in UV and visible region. ZnO nanorods and their array were grown by the chemical liquid technique on MgZnO films prepared by the sol-gel method. The results showed that ZnO nanorods were with wurtzite structure and oriented in the [002] c-axis direction.2.Three kinds of important devices were investigated in UV photodetectors.(1). MSM-type Schottky UV photodetectors of MgZnO films were developed. They responsiveness was excellent under the bias of 10V and within 300-375 nm.(2). ZnO nanorod Schottky-barrier UV photodetectors were developed. Their responsiveness of the devices showed that the devices have very good spectral response within 300-370 nm. The rejection ratio of UV to visible light was 864.3 under 5V bias. Also, the light current was three orders of magnitude greater than dark current. The responsiveness of 0.73 A/W and quantum efficiency of 21.9% were obtained under incident wavelength of 370 nm and bias of 5V.(3). Photo-conductive UV detectors of MgZnO nanorods array were developed. The optical absorption wavelength of MgOZnO nanorods was 315 nm, shorter than that of ZnO nanorods (370 nm).3.Dye-sensitized solar cells were prepared by using ZnO nano-crystalline with different grain sizes. The result showed that the ZnO nano-grains with different diameters affected remarkably on cells short circuit current and efficiency. Under the condition of AM 1.5 (optical density of 100mW/cm2, the cells efficiency with smaller grains(about 10 nm diameters) was 0.15%, about 2 orders of magnitude better than that with bigger grains...