Switching of Light Responsive Metal–Organic Gels from Insulator to Semiconductor: Flexible Smart Semiconducting Membranes for Optoelectronic Device Fabrication

Abstract

In the era of artificial intelligence and machine learning, semiconductor materials are the foundation of contemporary electronics and are essential for advancing technological innovation in widespread fields. Herein, we report a Ni-MOG (1) that undergoes gel-to-gel transformation, upon photochemical stimuli, via [2+2] reaction. It associates with the most spectacular change of green to yellow MOG (1′). Both the MOGs have shown an excellent ability to absorb nitrate salts of metals (M = Li, Mg) and transform to even stronger gels (1@M, 1′@M). The 1′@Li-MOG was found to be the strongest as the rigidity increased 51-fold. Our studies on their conductivity indicate that incorporation of metal-salts into MOGs significantly enhances the conductivity, which are otherwise insulators. Further, MOG 1′@Li found to exhibit the highest conductivity compared to 1@Mg, 1@Li, and 1′@Mg, in any three forms of measurements: pelleted, thin-film, and integration with mixed-matrix-membrane (MMM). The integration of Li-doped irradiated MOG with MMM exhibited the highest lithium-ion conductivity of 6.11 × 10⁻² S cm⁻¹ among all MOF/MOG-based materials. The ability of these materials to power LEDs highlights their potential for optoelectronic applications. We note here that these are the first reports of MOGs that transitioned from insulators to semiconductors upon undergoing [2+2] reaction and subsequent Li-doping.