采用低压化学气相沉积方法在玻璃衬底上制备了B掺杂的ZnO(BZO)薄膜, 通过氢退火对BZO进行处理, 然后作为前电极进行了非晶硅薄膜太阳能电池的制备及性能研究。结果表明: 在氢气气氛下退火后, BZO薄膜的载流子浓度基本无变化, 但Hall迁移率显著提高, 这使得BZO薄膜的导电能力提高; 当采用厚度较小、透光率较高的BZO薄膜进行氢退火后作为前电极结构时, 非晶硅薄膜太阳能电池的短路电流密度提高0.3~0.4 mA/cm2, 电池的转化效率提高0.2%。实验结果可为通过优化前电极结构来提高非晶硅薄膜太阳能电池转化效率提供一种简易的方法。

建立了SACM型In0.53Ga0.47As/In0.52Al0.48As雪崩光电二极管(APD)的分析模型, 通过数值研究和理论分析设计出高性能的In0.53Ga0.47As/In0.52Al0.48As APD。器件设计中, 一方面添加了In0.52Al0.48As势垒层来阻挡接触层的少数载流子的扩散, 进而减小暗电流的产生;另一方面, 雪崩倍增区采用双层掺杂结构设计, 优化了器件倍增区的电场梯度分布。最后, 利用ATLAS软件较系统地研究并分析了雪崩倍增层、电荷层以及吸收层的掺杂水平和厚度对器件电场分布、击穿电压、IV特性和直流增益的影响。优化后APD的单位增益可以达到0.9 A/W, 在工作电压(0.9 Vb)下增益为23.4, 工作暗电流也仅是纳安级别(@0.9 Vb)。由于In0.52Al0.48As材料的电子与空穴的碰撞离化率比InP材料的差异更大, 因此器件的噪声因子也较低。

采用一种新型的Nd∶YVO4/YVO4复合晶体,利用V型折叠腔,研究了高功率激光二极管端面泵浦的Nd∶YVO4/YVO4复合晶体激光器基频1.06 μm及倍频532 nm激光的输出特性.当泵浦功率为24.6 W时,获得1.06 pm激光的最大输出功率为11.7 W,光-光转换效率为48%.当泵浦功率为17 W时,获得了5.32 W的绿光输出,光-光转换效率达到31.3%.

Thermal effects control is very critical in highly scaling the output power of diode-pumped solid-state lasers to a few watts especially for end pumping configuration. Low temperature reservation of the pumping surface and the crystal could be adopted to reduce thermal effects and improve laser performance. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lensing theoretically based on the numerical heat analysis to the end-pumped anisotropic laser crystal. The temperature distribution in Nd:YVO4/YVO4 composite crystal was analyzed before the end-pumped Nd:YVO4/YVO4 composite crystal laser with V cavity was designed and set up. The maximum output powers of 9.53 W at 1064 nm, 5.01 W at 532 nm were obtained while the pumping power was 17 W. The highest optical to optical conversion efficiencies were up to 59.1% at 1064 nm and 34.4% at 532 nm, respectively.

Thermal effect in crystals is the main obstacle blocking diode-pumped solid state laser to get high and stable output power. Diffusion bonding crystal has been demonstrated to be an effective method to relieve the thermal lensing theoretically based on the numerical heat analysis to the end-pumped anisotropic laser crystal. The temperature distributions in Nd:YVO4/YVO4 composite crystal and conventional crystal were analyzed and compared. The end-pumped Nd:YVO4/YVO4 composite crystal laser was designed and set up with z-cavity. The maximum output powers of 9.87 W at 1064 nm and 6.14 W at 532 nm were obtained at the incident pump power of 16.5 W. The highest optical-optical conversion efficiencies were up to 59.8% at 1064 nm and 37.2% at 532 nm respectively.

在相同的实验条件下, 分别采用平平直腔和V型折叠腔对比了Nd:GdYVO4和Nd:YVO4两种晶体的基频和腔内倍频特性。采用平平直腔在抽运功率为10.64 W时分别获得了5.35 W、6.29 W的1.06 mm基频输出, 光－光转换效率达50.3％、59.1％, 斜效率达58.1％、68.8％；采用V型折叠腔KTP腔内倍频, 在抽运功率为6.71 W时分别获得了1.73 W和2.34 W的稳定倍频绿光输出, 光－光转换效率达25.8％、34.9％。比较得出, Nd:GdYVO4－KTP绿光激光器的平均输出功率及稳定性均低于Nd:YVO4－KTP绿光激光器。

在高功率激光二极管(LD)抽运的情况下, 对比分析了Nd:YVO4/YVO4复合晶体和Nd:YVO4单一晶体的激光特性。实验证明, 复合晶体能够有效地降低晶体内的温度梯度, 减小由端面变形带来的热透镜效应, 获得比单一晶体高出许多的输出功率。采用Z型折叠腔, 研究了Nd:YVO4/YVO4复合晶体KTP倍频特性, 当抽运功率为17 W时, 获得了6.23 W的绿光输出, 抽运光到绿光的转换效率高达37%。

利用激光二极管(LD)阵列侧面抽运声光(AO)调Q的Nd∶YAG激光器作为抽运源,研究了在不同声光重复频率和输出镜透过率的情况下,内腔式KTA-光参量振荡器(OPO)的输出特性。通过对单谐振光参量振荡器阈值公式的讨论,采用平凹腔的结构以及较短的腔长,降低了光参量振荡器的振荡阈值。当声光重复频率为4 kHz,输出镜透过率为30%,抽运电流为14.5 A时,光参量振荡器的1570 nm激光输出脉冲峰值功率达到5.6×104 W,脉冲宽度为2.5 ns,实验中最大平均输出功率为560.3 mW。结果表明,具有良好热性能的非线性晶体KTA是制造小型、轻便光参量振荡激光器的理想材料。

采用平凹短腔及V型折叠腔,研究了激光二极管端面抽运的Nd:Gd0.42Y0.58VO4激光器1.06mm及倍频532nm的输出特性。在输入抽运功率为11.05 W时,获得了1.06mm的最大平均输出功率为5.35 W,光-光转换效率达到48.42%；在输入抽运功率为6.8 W时,采用连续抽运和脉冲抽运分别获得了1.44 W和1.64 W的绿光输出,光-光转换效率分别为21.2%和24.1%。