This work investigate the formation of micro/nanostrucutred layers of silicon wafers having various conductivity types emphasizing the crucial role of laser in stimulating the etching reaction as well as controlling the silicon surface structures in photochemical and photoelectrochemical etching processes. A CW visible laser beam was used to synthesize silicon nanostructures of various morphologies in this work. It is found in photochemical etching that short laser wavelengths produce a thin porous layer compared to longer laser wavelengths which are appropriate for thicker porous layers. SEM investigation reveals the formation of different nanostructures that were synthesized by photochemical etching. Results show that optimum porosity of 70 %, 80 %, and 90 % are achievable for n, p, and p-n silicon respectively when using a current density of 25 mA/cm²in the photoelectrochemical etching process.

AFM images confirm that very small nanostructure features with average size of 80 nm can be obtained for p-n silicon in the photochemical etching process. Energy band diagrams of the three etching processes; Photochemical (PC), Electrochemical (EC) and Photoelectrochemical (PEC) provide good knowledge of the photogenerated/injected holes affecting the nanostructured surface formation. Image analysis software was used to examine the microstructuredsilicon surface produced by pulsed Nd:YAG laser. The thermal distribution profile showed that the surface temperature rises to about 2000 °C when a short laser pulse of 0.6 ms and high laser energy of 1 J were used. The surface and sub-surface temperature were estimated using COMSOL multiphysics software.

这项工作研究了具有各种导电类型的硅晶片的微/纳米结构层的形成，强调了激光在刺激蚀刻反应以及控制光化学和光电化学蚀刻过程中的硅表面结构方面的关键作用。在这项工作中，使用CW可见激光束来合成各种形态的硅纳米结构。在光化学蚀刻中发现，与较长的激光波长相比，较短的激光波长产生较薄的多孔层，而较长的激光波长适合于较厚的多孔层。SEM研究揭示了通过光化学蚀刻合成的不同纳米结构的形成。结果表明，对于n，p，n和p，可达到70％，80％和90％的最佳孔隙率^2.在光电化学蚀刻过程中。

AFM图像证实，在光化学蚀刻过程中，对于pn硅可以获得平均尺寸为80 nm的非常小的纳米结构特征。三种蚀刻工艺的能带图；光化学（PC），电化学（EC）和光电化学（PEC）提供了影响纳米结构表面形成的光生/注入孔的良好知识。使用图像分析软件检查脉冲Nd：YAG激光产生的微结构化硅表面。热分布曲线表明，当使用0.6 ms的短激光脉冲和1 J的高激光能量时，表面温度升高至约2000°C。使用COMSOL Multiphysics软件估算表面和亚表面温度。