A Mechanoresponsive Smart Window Based on Multifunctional Luminescent Solar Concentrator

A novel approach to creating a multifunctional smart window that combines electricity generation with transparency modulation is developed. The proposed smart window is based on a mechanoresponsive luminescent solar concentrator (LSC) composed of organic fluorophores (coumarin 6) impregnated into a compressible polymer matrix (polydimethylsiloxane, PDMS) that is surface‐modified on one side. In its initial state, the LSC is optically transparent but becomes increasingly opaque upon the application of compressive strain to the PDMS matrix, resulting in a higher optical shielding property and eventually becoming translucent. The smart window's degree of specular transmission can be reversibly adjusted between 20% and 84%, making it suitable for use as a switchable privacy window. Additionally, the LSC‐photovoltaic (PV) window maintains a high power conversion efficiency (PCE) even when in a translucent state with the privacy function enabled. Under AM1.5G solar irradiation (1 sun, 100 mW cm2), the LSC‐PV module achieves PCEs of 1.05–1.48% and optical efficiencies (ηopt) of 8.6–12.0%, depending on the strain. This technology holds significant promise for building‐integrated photovoltaics and smart window applications, such as privacy‐protecting windows, daylight‐controlling windows, power‐generating antinoise barriers, and transparent solar cells. Herein, a novel, multifunctional smart luminescent solar concentrator (LSC) window is introduced that has the unique ability to both regulate transparency and produce electricity. The window's transparency is controlled via reversible microwrinkles at the backside of polydimethylsiloxane LSC. The proposed LSC window maintains a high power conversion efficiency even when in a translucent state with the privacy function enabled.