Ag/Ga-doped ZnO/pyramidal silicon as a multifunctional surface-enhanced Raman scattering substrate

Abstract

High-performance surface-enhanced Raman scattering (SERS)-active substrate can be fabricated by deposited silver (Ag) nanoparticles on the pyramidal silicon with Ga-doped zinc oxide (ZnO) nanoneedles. Properly manufacturing a ZnO seed layer on pyramidal silicon may be beneficial to grow vertically aligned Ga-doped ZnO nanoneedles to deposit silver nanoparticles uniformly. Suitable silver sputtering duration on the Ga-doped ZnO nanoneedles has been upgraded to produce the most remarkable SERS effect in rhodamine 6G (R6G) molecules. SERS results show that Ag/Ga doped ZnO/pyramidal silicon is better than Ag/pyramidal silicon and Ag/silicon substrates. This phenomenon is attributed to Ag/Ga-doped ZnO/pyramidal silicon geometry, providing more hot spots and surface-active sites to exhibit high SERS enhancement, good reproducibility, and long-term stability. Ag/Ga doped ZnO/pyramidal silicon can also provide excellent SERS active substrates for detecting different types of drugs with low detection limits, such as amoxicillin (10−10 M) and irinotecan (10−7 M).