| In recent years, ultraviolet detection has been widely used in the military and civil. The solid detector material has large band gap, and it can also work in ultraviolet (UV) region, which could be applied to the UV photodetector. The ferroelectric thin films have a large number of applications in microelectronics and optoelectronics by virtue of their excellent properties, such as ferroelectric, piezoelectric, dielectric, pyroelectric, acousto-optic and nonlinear optical properties. The ferroelectric materials have good characteristic of spontaneous polarization, which can result in the depolarization field. When the ferroelectric thin film is illuminated with a given operating wavelength, the photovoltaic effect will occur, which can produce a large output voltage. Therefore, the excellent photoelectric property of the ferroelectric material has a great application prospect in ultraviolet-infrared detection.Due to the fact that Si substrate has strong absorption in UV-visible region, we choose the K9glass as an experimental substrate material. However, it is very difficult to grow the ceramic crystalline materials at the amorphous materials, and hence we investigated the preparation process of the LNO thin films grown on the K9glass substrate. We successfully obtain the LNO thin films with good performance by mean of RF magnetron sputtering technique and annealing method. Since the preparation of the ferroelectric thin films usually require a high temperature, however, the K9glass substrate can not withstand high temperature for a long time. Therefore, another important goal of this paper is to achivev a high performance detector at low temperatures by mean of the radio-frequency (RF) sputtering technique.The main results of this paper are as follow:(1) LaNiO3(LNO) thin films were grown on K9glass served as the buffer layer and the bottom electrode, respectively. XRD analysis has shown that the LNO thin films grown at room temperature has high preferred orientation (110) via a500℃and30minutes for annealing treatment. The ultraviolet-visible spectrophotometer analysis has shown that the annealed LNO films have different absorption strength for different lights. And the results also show that the electrical resistivity of the annealed LNO films decrease obviously compared with the untreated LNO films. (2) PZT thin films were fabricated on the LNO(110) thin film by mean of RF sputtering technique. By investigating the influence of different sputtering process on the PZT thin films, the optimized process conditions for achieving the high performance PZT thin films are obtained, the parameters are as follows:substrate temperature(550℃), sputtering power(93W), sputtering time(3h) and sputtering pressure(1.9Pa). The ultraviolet-visible spectrophotometer analysis has shown that the absorption rate of the samples can reache up to80%for the incident wavelength at300nm. The analysis of the TD-88A standardized ferroelectric test system has shown that the remained susceptibility is31.3μC/cm2for the5V test voltage. When the sample is illuminated with power of50W halogen, the electrometer (Keithley6514) alaysis has shown that the open-circuit voltage and short-circuit current of the samples are0.76V and19.4pA, respectively. |
