Performance Improvement of Photodetectors Based on ZIF-8 Nanostructures on Porous Silicon Substrate

• Main Authors: Ghafari, Shadi, Kazemzad, Mahmood, Naderi, Nima, Eshraghi, Mohamad Javad
• Format: Article
• Published: Springer 2024
• Subjects: QC Physics; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.um.edu.my/44758/; https://doi.org/10.1007/s11664-023-10892-y

Metal–organic frameworks (MOFs) have been widely used in optical devices due to their specific optoelectronic properties and compatibility with various substrates. Zeolitic imidazolate frameworks (ZIFs) are a subclass of MOFs with interesting optical and electrical properties. Specifically, ZIF-8 on a porous silicon (PS) substrate shows high mobility and improved charge transfer ability at low temperatures. In this research, significant improvement was obtained in detectivity, sensitivity, and noise equivalent power of fabricated photodetectors based on ZIF-8 nanostructures. According to the current–voltage curves, ZIF-8/PS samples required lower bias voltage in comparison with ZIF-8/Si for offering the same current. Therefore, the photodetectors based on ZIF-8/PS were low-power devices with many industrial applications. The morphology of nanostructures showed the deposition of more homogeneous and compact ZIF-8 layers on PS compared with the samples based on a non-porous silicon substrate, indicating the beneficial seeding effect of the porous substrate. According to the structural analysis, the polycrystalline ZIF-8 with dominant orientation of (011) was successfully grown on the PS (100) substrate. The higher photoluminescence intensity was recorded for the ZIF-8/PS sample due to its higher electron–hole coupling and surface-to-volume ratio. In order to study the optoelectronic properties of nanostructures, ZIF-8-based photodetectors were prepared and were exposed to various excitation wavelengths. The results indicated the temperature dependence of photocurrent. The photodetectors based on ZIF-8/PS nanostructures showed lower NEP, higher photoresponsivity, and better specific detectivity (D *) of 10.5 × 1013 cm Hz1/2 W−1 upon exposure to the incident illumination (λ = 365 nm) at 250 K. Graphical Abstract: Figure not available: see fulltext.. © 2024, The Minerals, Metals & Materials Society.