The photochemical core of every photosynthetic apparatus is the reaction center, a transmembrane enzyme that converts photons into charge‐separated states across the biological membrane with an almost unitary quantum yield. These findings pave the way for photo‐tunable inverters and ultimately for completely re‐addressable high‐performance circuits comprising optical storage units and ambipolar field‐effect transistors.Ī Bacterial Photosynthetic Enzymatic Unit Modulating Organic Transistors with Light A fully reversible light‐switching process is demonstrated, with a light‐controlled 100‐fold modulation of p‐type charge transport and a tenfold modulation of n‐type charge transport. Here for the first time, that tri‐component materials comprised of an ambipolar diketopyrrolopyrrole‐based semiconducting polymer combined with two different photochromic diarylethene molecules possessing ad hoc energy levels can be used to develop organic field‐effect transistors, in which the transport of both, holes and electrons, can be photo‐modulated. In this way, the combination of the pristine properties of each component is not only preserved but also combined with unprecedented properties emerging from the mutual interaction between the components. One of the grand challenges in organic electronics is to develop multicomponent materials wherein each component imparts a different and independently addressable property to the hybrid system. Link to article and accepted manuscript (open access). Phototuning Selectively Hole and Electron Transport in Optically Switchable Ambipolar Transistors