Oriented Growth of In-Oxo Chain based Metal-Porphyrin Framework Thin Film for High-Sensitive Photodetector

The potential of metal–organic frameworks (MOFs) for applications in optoelectronics results from a unique combination of interesting photophysical properties and the straightforward tunability using a large, ever growing set of organic and inorganic building units. Here, we demonstrate that using the MOF approach chromophores can be assembled into well-ordered 1D arrays using metal-oxo strands as lead structure. We demonstrate that the resulting porphyrinic rows exhibit unique photophysical properties and allow the realization of highly-sensitive photodetectors. A porphyrinic MOF thin film, SURMOF In-TCPP with [021] growth orientation, was fabricated using a layer-by-layer method, from In(NO3)3 and TCPP (5,10,15,20-(4-carboxyphenyl)porphyrin) linkers. A detailed experimental and theoretical analysis revealed that the assembly yields a structure where In-oxo strands running parallel to the substrate fix the chromophoric linkers in space to yield regular 1D arrays of porphyrins. The frontier orbitals of this highly anisotropic arrangement are localised in these columnar arrangements of porphyrins and give rise to a high photoactivity, which has been exploited to fabricate an efficient photodetector with a high responsivity of 7.28 × 1014 Jones for light with wavelength of 420 nm and short rise/fall times (0.10/0.05 s). This present work of oriented MOF thin film based high-sensitive photodetector for violet light provides a new avenue to combine the advantages of both inorganic and organic units for huge potential applications in optoelectronic devices.