Comprehensive investigation of structural, electrical, and optical properties for ZnO:Al films deposited at different substrate temperature and oxygen ambient
Comprehensive investigation of structural, electrical, and optical properties for ZnO:Al films deposited at different substrate temperature and oxygen ambient
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DOI：
10.1063/1.2901024
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发表时间：
2008-04-01
影响因子：
3.2
通讯作者：
Sun, Yuan-Ping
中科院分区：
文献类型：
--
作者：
Dong, Bin-Zhong;Hu, Hao;Sun, Yuan-Ping
采用脉冲激光沉积法在不同的衬底温度（T-s）和氧气气氛（P-O2）下制备了c轴取向的ZnO：Al（AZO）多晶薄膜。研究发现，随着T-s和P-O2的增加，AZO（0002）的2 θ位置向高角度移动，这与AZO薄膜中缺陷的数量和种类不同有关。此外，2 θ半高宽和（0002）摇摆曲线表明，不同条件下生长的AZO薄膜的结晶质量不同。同时，对于大多数样品，载流子浓度随着T-s和P-O2的增加而降低;然而，霍尔迁移率通常在适当的T-s和P-O2处达到最大值。此外，在不同条件下生长的AZO薄膜的电子输运可能受不同机制的控制。AZO的透射光谱表明，随着T-s和P-O2的增加，紫外吸收限和红外透过限向长波方向移动，这分别是由于光学带隙（E-g）和等离子体频率（ω（p））的变化。E-g和Ω（p）随T-s和P-O_2的变化规律与电学性质的变化规律一致。光致发光的强度与载流子浓度相关，表明AZO薄膜的室温发光主要是电子在导带和价带之间的跃迁。(c)2008年美国物理学会。
c-axis oriented polycrystalline ZnO:Al (AZO) films were deposited at different substrate temperature (T-s) and oxygen ambient (P-O2) by pulsed laser deposition. It is found that with the increase in T-s and P-O2, the 2 theta position of AZO (0002) shifts to higher angle, which can be attributed to the different amounts and species of defects in AZO films. Furthermore, the full width at half maximum of 2 theta and (0002) rocking curve indicate the different crystalline qualities for AZO films grown at different conditions. At the same time, the carrier concentration decreases with the increase in T-s and P-O2 for most of the samples; however, the Hall mobility usually attains its maximum at proper T-s and P-O2. Moreover the transport of electrons may be governed by different mechanisms for AZO films grown at different conditions. The AZO transmission spectra show that the ultraviolet absorption edge and infrared transparency limit shift toward longer wavelength with the increase in T-s and P-O2, which are due to the changes of optical band gap (E-g) and plasma frequency (omega(p)), respectively. Furthermore the evolutions of E-g and omega(p) with T-s and P-O2 are consistent with that of electrical properties. The intensity of photoluminescence is found to correlate with the carrier concentration which indicates that the transition of electrons between conduction and valence bands dominates the room temperature emission of AZO films. (c) 2008 American Institute of Physics.