Metal−organic frameworks (MOFs) are superior for multiple applications including drug delivery, sensing, and gas storage because of their tunable physiochemical properties and fascinating architectures. Optoelectronic application of MOFs is difficult because of their porous geometry and conductivity issues. Recently, a few optoelectronic devices have been fabricated by a suitable design of integrating MOFs with other materials. However, demonstration of laser action arising from MOFs as intrinsic gain media still remains challenging, even though some studies endeavor on encapsulating luminescence organic laser dyes into the porous skeleton of MOFs to achieve laser action. Unfortunately, the aggregation of such unstable laser dyes causes photoluminescence quenching and energy loss, which limits their practical application. In this research, unprecedently, we demonstrated ultralow-threshold (∼13 nJ/cm 2 ) MOF laser action by a judicious choice of metal nodes and organic linkers during synthesis of MOFs. Importantly, we also demonstrated that the white random lasing from the beautiful microflowers of organic linkers possesses a porous network, which is utilized to synthesize the MOFs. The highly luminescent broad-band organic linker 1,4-NDC, which itself exhibits a strong white random laser, is used not only to achieve the stimulated emission in MOFs but also to reduce the lasing threshold. Such white lasing has multiple applications from bioimaging to the recently developed versatile Li-Fi technology. In addition, we showed that the smooth facets of MOF microcrystals can show Fabry−Perot resonant cavities having a high quality factor of ∼10 3 with excellent photostability. Our unique discovery of stable, nontoxic, high-performance MOF laser action will open up a new route for the development of new optoelectronic devices.

Self-assembly of an environmentally friendly non-lanthanide barium-based metal–organic framework {[Ba­(2,6-ndc)­(H2O)2]·H2O} (1, 2,6-ndc = 2,6-naphthalenedicarboxylate) (Ba-MOF) is reported. The complex displays an intrinsic broad-band white light emission with a Commission International de I’Eclairage (CIE) index of (0.32, 0.33), and a corresponding yield of about 75%, when excited at a wavelength of 374 nm. The continuous broad band can be attributed to the inherent nature of Ba-MOF (1), i.e., interligand (π–π*) and ligand–metal charge transfer mechanisms, resulting in a white light emission. Moreover, a device is fabricated using a nanometer-scale thin film of Ba-MOF (1) as an active material and the resulting device exhibits a white electroluminescence spectrum. In comparison with the traditional two-component light-emitting diodes (LEDs), this MOF-based white light LED system has significant advantages such as its ability to function as a phosphor-free, single-component broad-band emitter, high stability, low cost, and minimal environmental footprints. Density functional theory (DFT) calculations are carried out to better comprehend the origin of this white light emission from 1. This Ba-MOF-based white light emitter has the potential for being an environmentally friendly and low-cost source for white light solid-state applications.