光电探测器利用光电效应将光信号转换为电信号，在通信、安防监控、医疗诊断等领域应用广泛。近年来，ZnO（E_g=3.37 eV）因其宽带隙、高电子迁移率、易制备等特性作为光电探测器的理想材料备受关注。然而，纯ZnO纳米材料的光电性能受表面状态、结构缺陷、晶体质量和沉积工艺等因素的制约，影响了载流子传输和寿命，导致器件性能不佳。本论文引入异质结结构，将ZnSe和ZnO纳米材料结合成异质结结构光电探测器，提高了器件的灵敏度和响应速度。这种设计不仅克服了ZnO器件的性能不佳的影响，还在波长选择性、响应速度等性能方面取得显著提升。基于ZnSe和ZnO的异质结结构光电探测器在紫外至可见光范围内表现出优异性能，具备高稳定性和制备可行性。这种异质结结构光电探测器有望成为光电子器件领域的重要发展方向，为实现更高性能和更广泛应用的光电探测器提供了新的技术支持。以下是主要研究内容：

（1）利用溶胶-凝胶和水热法，采用单因素实验来制备ZnO种子层和ZnO纳米棒阵列。首先，通过改变退火温度和溶胶溶剂种类来优化ZnO种子层的制备工艺，之后通过改变水热法工艺中的Zn²⁺浓度和[Zn²⁺]/[(CH₂)₆N₄]浓度比来优化ZnO纳米棒阵列。通过SEM和XRD表征ZnO种子层和ZnO纳米棒阵列结构和形貌，PL谱测试表征其光学性能。优化后的工艺参数为：溶胶溶剂为乙二醇甲醚，退火温度400 ℃、水热[Zn²⁺]/[(CH₂)₆N₄]浓度比为1:3、水热Zn²⁺浓度为0.04 mol/L。优化后所得的ZnO纳米棒阵列的光学性能相对较好。

（2）在使用优化工艺制备的ZnO纳米棒阵列的基础上，通过水溶液化学法制备了ZnO/ZnSe复合纳米棒阵列，并对其进行了形貌、结构和光电性能的研究。结果表明：ZnO纳米棒阵列光电探测器器件的暗电流为1.79 mA，光电流为333 mA，光电响应为186。且ZnO纳米棒阵列光电探测器器件的电流并没有急剧下降，光电响应和恢复过程都比较缓慢，出现了光电导弛豫现象。ZnO/ZnSe复合纳米棒阵列光电探测器器件的暗电流为0.0361 mA，光电流为43.9 mA，光电响应为1216。这是由于异质结结构的存在，ZnO纳米棒/ZnSe纳米颗粒可以有效分离光生载流子，延长电子和空穴重组所需时间，从而提高了ZnO/ZnSe复合纳米棒阵列光电探测器器件的光电流。

（3）通过改变反应温度和Se浓度两个单因素，制备ZnO/ZnSe复合纳米棒阵列，并研究这两个单因素对ZnO/ZnSe复合纳米棒阵列结构和形貌的影响，随后进行光电性能测试。随着反应温度的提高，ZnO/ZnSe复合纳米棒阵列中存在Se单质，其影响了器件的光电性能。优化的工艺参数为：Se浓度为0.010 mol/L，反应时间30 min，反应温度为55 ℃。优化参数所制备的ZnO/ZnSe复合纳米棒阵列光电探测器器件的暗电流为1.7×10^-7 A，光电流为1.002×10^-3 A，光电响应为5894.2。

Photodetectors use the photoelectric effect to convert light signals into electrical signals, and are widely used in fields such as communication, security monitoring, and medical diagnosis. In recent years, ZnO (Eg=3.37 eV) has attracted much attention as an ideal material for photodetectors due to its wide bandgap, high electron mobility, and ease of preparation. However, the optoelectronic properties of pure ZnO nanomaterials are constrained by factors such as surface state, structural defects, crystal quality, and deposition process, which affect carrier transport and lifetime, resulting in poor device performance. This Thesis introduces a heterojunction structure and combines ZnSe and ZnO nanomaterials to form a heterojunction structure photodetector, which improves the sensitivity and response speed of the device. This design not only overcomes the poor performance of ZnO devices, but also achieves significant improvements in wavelength selectivity, response speed, and other performance aspects. Heterojunction photodetectors based on ZnSe and ZnO exhibit excellent performance in the ultraviolet to visible light range, with high stability and fabrication feasibility. This heterojunction structure photodetector is expected to become an important development direction in the field of optoelectronic devices, providing new technical support for achieving higher performance and wider applications of photodetectors. The following are the main research contents:

(1) ZnO seed layers and ZnO nanorod arrays were prepared by single factor experiments using sol-gel and hydrothermal methods. Firstly, the preparation process of ZnO seed layer was optimized by changing the annealing temperature and the type of sol solvent. Then, the ZnO nanorod array was optimized by changing the Zn²⁺concentration and the [Zn²⁺]/[(CH₂) ₆N₄] concentration ratio in the hydrothermal process. Characterization of ZnO seed layer and ZnO nanorod array structure and morphology by SEM and XRD, and characterization of their optical properties by PL spectroscopy. The optimized process parameters are as follows: the sol solvent is ethylene glycol methyl ether, the annealing temperature is 400 ℃, the hydrothermal [Zn²⁺]/[(CH₂) ₆N₄] concentration ratio is 1:3, and the hydrothermal Zn²⁺concentration is 0.04 mol/L. The optical properties of the optimized ZnO nanorod array are relatively good.

(2) On the basis of using optimized processes to prepare ZnO nanorod arrays, ZnO/ZnSe composite nanorod arrays were prepared by aqueous solution chemistry method, and their morphology, structure, and optoelectronic properties were studied. The results showed that the dark current of the ZnO nanorod array photodetector device was 1.79  mA, the photocurrent was 333  mA, and the photoelectric response was 186. And the current of the ZnO nanorod array photodetector device did not sharply decrease, and the photoelectric response and recovery process were relatively slow, resulting in the phenomenon of photoconductivity relaxation. The dark current of the ZnO/ZnSe composite nanorod array photodetector device is 0.0361 mA, the photocurrent is 43.9 mA, and the photoelectric response is 1216. This is due to the presence of heterojunction structures, where ZnO nanorods/ZnSe nanoparticles can effectively separate photo generated charge carriers, prolong the time required for electron and hole recombination, and thus improve the photocurrent of ZnO/ZnSe composite nanorod array photodetectors.

(3) By changing the reaction temperature and Se concentration as two single factors, ZnO/ZnSe composite nanorod arrays were prepared, and the effects of these two single factors on the structure and morphology of ZnO/ZnSe composite nanorod arrays were studied. Subsequently, photoelectric performance tests were conducted. As the reaction temperature increases, Se exists in the ZnO/ZnSe composite nanorod array, which affects the optoelectronic performance of the device. The optimized process parameters are: Se concentration=0.010 mol/L, reaction time 30 min, reaction temperature=55 ℃. The dark current of the ZnO/ZnSe composite nanorod array photodetector device prepared by optimizing parameters is 1.7 × 10^-7 A, the photocurrent is 1.002 × 10^-3 A, and the photoelectric response is 5894.2.

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