Title: Cost-effective fabrication of porous silicon for optical biosensing applications

Abstract:

In optical biosensing technique, since the reactions are generally carried out only in close proximity to the electrode surface, the electrodes themselves play a crucial role in the performance. Here, the method for cost-effective fabrication of porous silicon (PSi) electrode is proposed, that can be used as a biosensor substrate due to its large surface area, good refractive index, high biocompatibility, and reproducibilty without any surface modification. If resistivity of silicon wafer is increased, the wafer cost is decreased. Hence, the high resistive p-type silicon wafer is used here to fabricate the PSi. Electrochemical etching process is used to synthesize the PSi from the high resistive bulk silicon. The etching parameters like current density is maintained as constant as 10 mA/cm² and etching time are varied as 60, 120 and 180 min. Electrochemical etchant like HF and isopropanol are mixed in the ratio of 1:2. The porosity is determined by gravimetric method and the photoluminescence and spectrum absorption are investigated by using the spectroflurometer. The formed PSi surface morphology is analyzed using SEM study. The obtained photoluminescence response shows that if the porosity is increased, then the band gap is increased. The maximum porosity achieved is 84.21% for the etching time 180 mins and maximum energy band gap is obtained as 1.8921 eV for the wavelength 655.35 nm with refractive index of 2.874. The results revealed that the fabricated PSi substract has uniform pores with larger surface area and good refractive index which is needed requirement for optical biosensing applications.

Biography:

S Praveen Kumar has completed his PhD at the age of 34 years from Anna University. He is working as professor and he is the head for centre for micro nano design and fabrication, saveetha engineering college, chennai. He has published more than 15 papers in reputed journals and has been serving as an reviewer member of many reputed journals. His research area includes MEMS, BioMEMS, Microfluidics, Biosensors, Nanosynthesis, etc.