The Effect of PSi Pore Structure on the Characteristics of ZnO Rods Fabricated by Hydrothermal Method

Modifying photo-anode structures in DSSC devices is still challenging in improving efficiency. This study focused on the ZnO rod growth on several porous silicon substrates using the hydrothermal method and determining which porous silicon is appropriate for DSSC applications. The materials used for the growth solution were Zn(NO۳)۲۶H۲O ۰.۰۵ M and C۶H۱۲N۴ ۰.۲۵ M. The hydrothermal process was carried out at ۹۰°C for ۶ h and then annealed at ۴۵۰°C for ۳۰ min. SEM revealed that PSi pore influences the structure, diameter, and density of ZnO rods. ZnO structures formed in ZnO rods with a dominant vertical growth direction, ZnO rods with an intersection direction, and flower-like ZnO rods. The diameter of the PSi pore affected the density of ZnO rods grown on the PSi. The average diameter size and the density of ZnO rods vary from ۷۴۷.۶۶-۱۶۱۰.۶۸ nm and ۰.۲۲-۰.۹۰ rod/μm۲. XRD confirmed the presence of ZnO hexagonal wurtzite, Si cubic, and SiO۲ monoclinic. UV-Vis spectrometry characterization results showed that sample reflectance was influenced by ZnO rod density and PSi pitch. The larger density of ZnO rods and the smaller pitch of the PSi pore will lead to lower reflectance. In addition, band gap values were obtained in the ۳.۰۶-۳.۷۵ eV range. FTIR identified the existence of a ZnO vibration bond, indicating that ZnO was successfully grown on all PSi substrates. The ZnO rods grown on P۱۵S۱۱۸۰ are expected to have more appropriate properties among all five samples for DSSC photoanode.

کلیدواژه ها:

ZnO like-flower ، Hydrothermal ، Reflectance ، Porous silicon ، ZnO rods