Surface passivation and thermally treated porous silicon for Schottky photodetector application / Nurul Ashiqin Mohd Nazir

This study addresses the natural limitations of porous silicon (Psi), including instability, oxidation, degradation, and fragility, which limit its use in advanced optoelectronic devices such as Schottky photodetectors. These issues have been caused by Psi's extremely sensitive surface and structural defects, which result in poor reliability and performance. This study aims to enhance the stability and optoelectronic characteristics of Psi by surface passivation with SiO2 and thermal treatment with 450oC methods. SILVACO TCAD simulations were used to produce and characterize Psi in various kinds of conditions, including untreated, passivated, and thermally treated structures. The key parameters examined are dark current (Id), photocurrent (Ip), Schottky barrier height (SBH), current gain, and spectral response. The results indicated that treated passivated Psi structure (PSSO4) excelled over all other structures. It obtained an SBH of 0.9503 eV, a significantly reduced dark current of 2.59 x 10~10 A at 5 V, and a peak spectral response at 500 nm, which relates to an energy gap of 2.48 eV. These enhancements are due to the combined effect of passivation and thermal treatment, which successfully reduced surface defects, stabilised the porous structure, and improved charge carrier movement. The study shows that surface passivation and thermal treatment are useful ways to reduce Psi's limitations, making it a suitable candidate for next-generation optoelectronic applications. These findings help encourage the development of dependable, high-performance Psi-based devices for optoelectronic innovations through improving stability and optoelectronic performance.