论文部分内容阅读
使用水热法在石英衬底上制备了掺铝氧化锌(AZO)薄膜,采用X射线衍射仪、扫描电子显微镜和低温光致发光谱技术对薄膜的微结构和发光性能进行了表征。结果表明,薄膜由氧化锌纳米锥构成,纳米锥直径大部分都在100 nm以下,且具有明显的沿c轴择优生长的特征。此种方法制备的AZO薄膜在室温下存在两个较宽的发光峰,即紫外-紫光发光峰和绿光-红光发光峰。铝掺杂强烈地影响两个发光峰的相对强度。随着掺杂量的增大,(1)紫外-紫光发光峰的相对强度和绝对强度都迅速增大,并在铝掺杂量达到10%时达到最大值,(2)绿光-红光发光峰中,各子发光峰的相对强度也发生一定变化,主要表现为长波子发光峰的发光强度的相对增大。铝掺杂还导致薄膜的发光谱中出现一个极少见的位于355 nm处的发光峰,该发光峰随铝掺杂量的增大而增强。薄膜的低温光致发光谱表明,随着薄膜温度由10 K升高到267 K,薄膜的紫外-紫光发光峰变化不明显,但绿光-红光发光峰的强度则随着温度的增加而快速单调减小,呈现荧光热猝灭现象。由发光中心的多声子发射造成的非辐射激子复合应该是造成这种热猝灭的主要原因。
The AZO films were prepared on quartz substrates by hydrothermal method. The microstructures and luminescent properties of the films were characterized by XRD, SEM and low temperature photoluminescence. The results show that the thin film is composed of zinc oxide nanocones. The diameter of the nanocones is mostly below 100 nm and has the obvious feature of preferential growth along the c axis. AZO films prepared by this method have two broad emission peaks at room temperature, namely UV-violet light and green-red light. Aluminum doping strongly affects the relative intensities of the two luminescence peaks. With the increase of doping amount, (1) the relative intensities and absolute intensities of UV-violet luminescence peaks increase rapidly and reach the maximum value when aluminum doping amount reaches 10%, (2) green-red light In the luminescence peak, the relative intensity of each luminescence peak also changes a little, mainly showing the relative increase of the luminescence intensity of the long-wavelength luminescence peak. Aluminum doping also results in an extremely rare luminescence peak at 355 nm in the emission spectrum of the film, which increases with the increase of the doping amount of aluminum. The low-temperature photoluminescence spectra of the films showed that the UV-violet luminescence peaks of the films did not change obviously with the increase of the film temperature from 10 K to 267 K, but the intensities of the green-red luminescence peaks increased with the increase of the temperature Fast monotonous decrease, showing fluorescence quenching phenomenon. The non-radiative exciton recombination caused by the multi-phonon emission of the luminescent center should be the main cause of this thermal quenching.