中文摘要：

为了进一步改善Si/SiC异质结光电二极管的性能,采用类似掺杂超晶格的结构,将Si层由多个具有量子尺寸的p型薄层和n型薄层周期性地叠合而成,在Si层中形成一系列不同层的电子势阱和空穴势阱,以延迟光生载流子的复合,延长光生载流子的复合寿命,达到提高光电流密度的目的。使用Silvaco软件模拟了这种Si/SiC异质结的特性,研究了不同的Si层结构参数对器件光电特性的影响,并对Si层的厚度及掺杂浓度进行了优化。研究表明,在0.6 W/cm^2的卤钨灯辐照条件下,从SiC侧入射,p-Si和n-Si层的掺杂浓度均为1018 cm^3,厚度均为10 nm,器件的光电流密度可达129.6 mA/cm^2,与常规结构相比,其最大光电流密度提高了21%,表明将Si/SiC异质结的Si层做成调制掺杂结构对器件光电性能有显著的改善作用。

英文摘要：

The Si doping superlattice structure was adopted to improve the properties of the Si/SiC heterojunction photodiode.The Si layer was comprised of periodically alternating n-Si and pSi layers with the quantum size.A series of electron traps and hole traps of different layers were formed in the Si layer to delay the light carrier recombination,extend the light carrier recombination lifetime and improve the photocurrent density.The properties of the Si/SiC heterojunction device were simulated by Silvaco software,the effects of the different Si layer structural parameters on the optoelectronic properties were studied,the thickness and doping concentration of the Si layer were optimized.The study shows that under a halogen tungsten lamp irradiation condition of 0.6 W/cm^2 from the SiC side,the photocurrent density of the Si/SiC heterojunction reaches 129.6 mA/cm^2 when the doping concentrations of the p-Si and n-Si layers are all 1018 cm^-3 respectively and the thicknesses of the p-Si and n-Si layers are all 10 nm.Comparing with the conventional structure,the maximum photocurrent density of the device increases by 21%,showing that the modulation-doping Si layer of the Si/SiC heterojunction can obviously improve the photocurrent properties.