High-performance broadband SiC nanoparticles/porous silicon photodetector prepared by laser ablation in liquid.

Improving the figures of merit of heterojunction photodetectors has attracted significant research attention due to the growing demand for high-performance optoelectronic devices in advanced industrial and technological applications. The integration of nanomaterials with a porous silicon structure substrate offers an effective approach to enhance the light absorption, carrier separation efficiency, and interfacial charge transport in silicon-based photodetectors. Here, we report the fabrication of a SiC nanoparticles/porous silicon heterojunction photodetector. The SiC nanoparticles (NPs) are synthesized by laser ablation of a silicon target in ethanol, and porous silicon (PSi) is fabricated by electrochemical anodization. The X-ray diffraction studies reveal that the synthesized SiC nanoparticles are crystalline in nature with a hexagonal structure (α-SiC phase). The energy gap of the SiC colloidal nanoparticles was found to be 3.75 eV. Scanning electron microscopy (SEM) investigations showed the formation of spherical SiC nanoparticles with an average particle size of 65.5 ± 18 nm. The electrical properties and photoresponse of the SiC/(n,p) PSi photodetectors were investigated. The responsivity and detectivity of the SiC NPs/p-PSi photodetector were 1.44 A W-1 and 3.07 × 1011 Jones at 450 nm, respectively, while SiC NPs/n-PSi exhibited a responsivity of 0.9 A W-1 and a detectivity of 1.83 × 1011 Jones at 450 nm. The photocurrent-time-dependent results revealed that the rise time/fall time ratios (τ r/τ f) of SiC NPs/p-PSi and SiC NPs/n-PSi photodetectors were 248 ms/306 ms and 168.8 ms/190.9 ms, respectively, and the corresponding ON/OFF current ratio was 137 and 30.