In this work, a two-step metal organic chemical vapor deposition (MOCVD) method was applied for growing β-Ga₂O₃ film on c-plane sapphire. Optimized buffer layer growth temperature (T_B) was found at 700 °C and the β-Ga₂O₃ film with full width at half maximum (FWHM) of 0.66° was achieved. A metal?semiconductor?metal (MSM) solar-blind photodetector (PD) was fabricated based on the β-Ga₂O₃ film. Ultrahigh responsivity of 1422 A/W @ 254 nm and photo-to-dark current ratio (PDCR) of 10⁶ at 10 V bias were obtained. The detectivity of 2.5 × 10¹⁵ Jones proved that the photodetector has outstanding performance in detecting weak signals. Moreover, the photodetector exhibited superior wavelength selectivity with rejection ratio (R_{250 nm}/R_{400 nm}) of 10⁵. These results indicate that the two-step method is a promising approach for preparation of high-quality β-Ga₂O₃ films for high-performance solar-blind photodetectors.

采用金属有机化学气相沉积（MOCVD）工艺在p-GaAs（100）衬底上外延了Ga₂O₃薄膜并制备了n-Ga₂O₃/p-GaAs异质结日盲紫外探测器。通过X射线衍射仪、原子力显微镜、场发射扫描电子显微镜等方法对Ga₂O₃薄膜表面形貌、晶体质量进行了测试与分析。结果表明，Ga₂O₃薄膜呈单一晶向，薄膜表面平整且为Volmer-Weber模式外延。测试表明，n-Ga₂O₃/p-GaAs异质结探测器具有明显的整流特性。器件在5 V反向偏压和紫外光（254 nm）照射下实现了超过3.0×10⁴的光暗电流比、7.0 A/W的响应度、3412%的外量子效率、4.6×10¹³ Jones的探测率。我们利用TCAD软件对器件结构进行仿真，得到了器件内的电场分布和能带结构，并分析了器件的工作原理。该异质结探测器性能较好，制造工艺简单，为Ga₂O₃超灵敏日盲紫外探测器的研制提供了新途径。

InGaAs/AlGaAs多量子阱（MQWs）作为一种常见的Ⅲ?Ⅴ族外延材料，通常应用于半导体激光器和太阳能电池等领域。然而，由于量子阱的势阱层和势垒层生长温度不同，铟原子的偏析和多量子阱生长质量较差等问题尚未得到很好的解决。本文设计了一种砷化镓（GaAs）材料作为插入层（ISL），并用于InGaAs/AlGaAs MQWs的结构。PL、XRD、AFM测试表明，GaAs插入层保证了MQWs结构中更多的辐射复合，阻止了铟原子的偏析。但GaAs插入层的引入也会产生“局域态”，影响量子阱的发光性质。本研究可以加深对InGaAs/AlGaAs多量子阱辐射复合机制的理解，并且对引入GaAs插入层的InGaAs/AlGaAs多量子阱发光性质的研究具有重要意义。

采用脉冲直流磁控溅射法在Si（100）衬底上制备了AlN/Mo/Sc_0.2Al_0.8N复合结构薄膜，在该结构上通过金属有机化学气相沉积（MOCVD）技术进行GaN薄膜的外延。使用原子力显微镜、高分辨X射线衍射、粉末X射线衍射、扫描电子显微镜和拉曼光谱研究了Mo插入层的厚度对Sc_0.2Al_0.8N缓冲层和GaN外延层晶体质量的影响，研究了Sc_0.2Al_0.8N缓冲层对Mo上生长的GaN外延层的影响。研究结果表明，Mo插入层的厚度是影响Sc_0.2Al_0.8N缓冲层和GaN外延层的重要因素，Sc_0.2Al_0.8N缓冲层对Mo上GaN晶体质量的提高具有重要意义。随Mo厚度的增加，Sc_0.2Al_0.8N缓冲层的表面粗糙度先减小后增大，GaN外延层的（002）面X射线衍射摇摆曲线半峰全宽先减小后增大。当Mo插入层厚度为400 nm时，GaN外延层的晶体质量最好，GaN（002）面的X射线衍射摇摆曲线半峰全宽为0.51°，由拉曼光谱计算得到的压应力483.09 MPa；直接在Mo上进行GaN的外延，GaN（002）面的X射线衍射摇摆曲线半峰全宽无法测得，说明在Mo上进行GaN的外延需要Sc_0.2Al_0.8N缓冲层。

Homoepitaxial growth of Si-doped β-Ga₂O₃ films on semi-insulating (100) β-Ga₂O₃ substrates by metalorganic chemical vapor deposition (MOCVD) is studied in this work. By appropriately optimizing the growth conditions, an increasing diffusion length of Ga adatoms is realized, suppressing 3D island growth patterns prevalent in (100) β-Ga₂O₃ films and optimizing the surface morphology with [010] oriented stripe features. The slightly Si-doped β-Ga₂O₃ film shows smooth and flat surface morphology with a root-mean-square roughness of 1.3 nm. Rocking curves of the (400) diffraction peak also demonstrate the high crystal quality of the Si-doped films. According to the capacitance–voltage characteristics, the effective net doping concentrations of the films are 5.41 × 10¹⁵ – 1.74 × 10²⁰ cm⁻³. Hall measurements demonstrate a high electron mobility value of 51 cm²/(V·s), corresponding to a carrier concentration of 7.19 × 10¹⁸ cm⁻³ and a high activation efficiency of up to 61.5%. Transmission line model (TLM) measurement shows excellent Ohmic contacts and a low specific contact resistance of 1.29 × 10^-4 Ω·cm² for the Si-doped film, which is comparable to the Si-implanted film with a concentration of 5.0 × 10¹⁹ cm⁻³, confirming the effective Si doing in the MOCVD epitaxy.

针对高应变InGaAs/GaAs多量子阱中存在的局域态问题，利用金属有机化合物气相外延（MOCVD）技术，设计并生长了五周期的In_0.3Ga_0.7As/GaAs高应变多量子阱材料。通过原子力显微镜（Atomic force microscope，AFM）和变温光致发光（Photoluminescence，PL）测试，发现量子阱内部存在缺陷及组分波动的材料无序性表现，验证了多量子阱内部局域态的存在及起源。同时发现在不同测试位置，局域态在低温下对光谱的影响也不同，分别表现为双峰分布和峰位“S”型变化。这进一步说明材料内部无序化程度不同，导致局域态的深度也不同。依据温度?带隙关系的拟合，提出了包含局域态的多量子阱材料的电势分布，并揭示了局域态载流子和自由载流子的复合机制。并且借助变功率PL测试，研究了在不同激发功率密度下不同深度的局域态的发光特性。

提出了采用金属有机化学气相沉积（MOCVD）生长无Ga且应力平衡的InAsP/InAsSb超晶格，并探索了其作为红外吸收材料的可行性。首先采用k·p理论计算了InAsP/InAsSb超晶格的带隙，发现其波长调节范围可以从中波红外到长波红外。然后通过MOCVD技术在InAs衬底上生长了InAs_0.8P_0.2/InAs_0.7Sb_0.3超晶格。XRD测试结果表明，InAs衬底峰与超晶格零级卫星峰的失配仅61"，即基本实现应力平衡；AFM测试材料表面形貌显示5 μm×5 μm范围内均方根粗糙度为0.4 nm；低温PL光谱显示较强的发光，峰位于3.3 μm的中波红外波段，接近设计值。这些结果表明采用MOCVD生长应力平衡的InAsP/InAsSb超晶格作为红外探测材料具有较好的可行性和实用性。