Perylene derivatives possess large absorptivity and high quantum yields (QYs) and thus are promising luminophores for luminescent solar concentrators (LSCs). Unfortunately, severe aggregation-caused quenching, poor solubility, and large reabsorption significantly reduce their solid-state photoluminescence. To address these issues, perylene tetracarboxylic acid (PTCA) is prepared by hydrolyzing perylene tetracarboxylic dianhydride in sodium hydroxide, which is highly compatible with amino-silane precursors for in situ sol–gel synthesis of the silica matrix. In this case, highly luminescent and transparent PTCA@silica composites are formed, in which PTCA mainly exists in the monomer species due to covalent crosslinking to silica network structures. Therefore, a near-unity solid-state QY of ≈90% is obtained even at elevated loadings and existence of reabsorption due to the preservation of monomer states and efficient photon recycling. To demonstrate their potentials in LSCs, large-area LSCs ((Formula presented.)) with laminated configuration are fabricated, yielding a high power conversion efficiency of 1.1%. To mitigate the escape-cone losses, the LSCs can be integrated with holographic grating, reaching an ultrahigh edge-emission efficiency of 90%.