Abstract

Undoped and Al-doped zinc oxide (AZO) layers, greatly transparent and with high mobility, have been prepared at low substrate temperature using a chemical reactive spray technique. The effect of aluminum incorporation in the zinc oxide (ZnO) lattice has been characterized by means of X-ray powder diffraction, Raman spectroscopy, electrical and optical measurements. AZO layers reveal a hexagonal wurtzite structure whose lattice parameter decreases with increasing Al content and whose crystal quality decreases for Al content higher than 2%. Low resistivity AZO films have been found for 3% Al content. Additionally, AZO layers exhibit a blue shift of the optical gap with the increase of Al content that is attributed to the Burstein–Moss effect due to the increase of the charge carrier concentration. A density of free electron greater than 2.0 × 10¹⁹ cm^–3 is obtained for the AZO thin films with 5% Al. Our results encourage the use of AZO films deposited at a low temperature as electrodes and optical windows in photovoltaic devices.

中文翻译：

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喷雾热解沉积ZnO薄膜的铝掺杂

摘要

已经使用化学反应喷涂技术在低基材温度下制备了高度透明且具有高迁移率的未掺杂和Al掺杂的氧化锌（AZO）层。通过X射线粉末衍射，拉曼光谱，电学和光学测量来表征铝结合在氧化锌（ZnO）晶格中的作用。AZO层显示六方纤锌矿结构，其晶格参数随Al含量的增加而降低，而Al含量高于2％时其晶体质量下降。发现低电阻率的AZO膜的铝含量为3％。此外，随着电荷载流子浓度的增加，由于Burstein-Moss效应，AZO层随Al含量的增加而呈现出光学间隙的蓝移。自由电子的密度大于2.0×10对于含5％Al的AZO薄膜，可得到¹⁹ cm ^–3。我们的研究结果鼓励将低温沉积的AZO膜用作光伏器件中的电极和光学窗口。