一维氧化锌柱阵列空间取向激发的荧光光谱研究

Photoluminescence of One Dimension ZnO Single Crystal Columns Array Excited by Different Space Variation Direction

用两步气相沉积-氧化法制备了具有高度一致指向性的一维纤锌矿六方结构的氧化锌单晶柱阵列,探测它的不同空间取向激发条件下的荧光光谱。结果表明,一维阵列样品在不同空间取向的激发光照射下,其荧光光谱有明显变化。当低功率35 5nm激光对一维方向进行横向激发时,激子发光的相对强度较大;当用10 6 4nm激光取向激发时,发射光谱的差异更明显。除了荧光光谱的发射峰强弱发生变化外,在一维横向激发时上转换发射光谱产生了新的发射峰,表明在不同的取向激发下一维阵列样品对激发光的吸收有明显变化。由此产生的荧光发射的差异非常明显,表明一维氧化锌柱阵列对能量吸收、能量传递等有很强的方向性。上转换偏振光谱表明,当偏振光的振动方向与阵列的一维方向平行时,发射光谱中4 0 0nm的发光峰强度比偏振方向与一维方向垂直时要大,表明偏振方向对一维阵列的空间取向激发荧光光谱是有影响的。在讨论阵列发光性质如发光光谱,发射强度的时候,必须明确激发光的强度。

Highly-oriented single crystal ZnO columns array was prepared by a simple two-step evaporation oxidation method. And the photoluminescence properties of different direction excitation were investigated. Upon different direction excitation, the emission spectra were greatly different. Besides the relative intensity of different emission peak of PL changed; some new emission peaks were also detected at high excitation power. This showed that the energy absorption, transmission and emission in one dimension ZnO column array were directional. The up-conversion polarized photoluminescence spectra were also found, and the intensities of 400 nm emission peak were affected by the laser polarization orientation. These results showed that the intensity and shape of PL were related with the direction and polarization of the excitation laser. The results also give some important references for subminiature one dimension line array optoelectric device.