脉冲激光沉积法制备的ZnO薄膜的低阈值电抽运紫外随机激射

摘要

分别采用直流反应溅射法和脉冲激光沉积法在硅衬底上沉积ZnO薄膜，用X射线衍射、扫描电镜、光致发光谱等手段对两种方法沉积的ZnO薄膜的结晶状态、表面形貌和光致发光等进行了表征。进一步对比研究了以上述两种方法制备的ZnO薄膜作为发光层的金属-绝缘体-半导体结构器件的电抽运紫外随机激射。结果表明，与以溅射法制备的ZnO薄膜作为发光层的器件相比，以脉冲激光沉积法制备的ZnO薄膜为发光层的器件具有更低的紫外光随机激射阈值电流和更高的输出光功率。这是由于脉冲激光沉积法制备的ZnO薄膜中的缺陷更少，从而显著地减少了紫外光在光散射过程中的光损耗。%ZnO films on silicon substrates are prepared by reactive sputtering and pulsed laser deposition, respectively. Their crystallini-ties, surface morphologies and photoluminescence actions are characterized using X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy correspondingly. Furthermore, the electrically pumped random laser actions of the two metal-insulator-semiconductor structured devices based on the sputtered and pulse laser deposition ZnO films respectively are comparatively investigated. It is found that the device fabricated using the pulse laser deposition ZnO film possesses a much lower threshold current for random lasing and higher output optical power. This is due to the fact that the pulse laser deposition ZnO film has much fewer defects, leading to remarkably lower optical loss during the multiple scattering within such a ZnO film.