A new single-layered organic photodetector was prepared, which exhibited a high photomultiplication gain of 356 at 830 nm.

Photoconductive Y‐TiOPc nanoparticles (NPs) (dav = 3.4 nm), well dispersible in 1,2‐dichloroethane, are efficiently prepared via a colloidal‐solution‐mediated phase‐transition process. Single‐layered photoreceptors composed of Y‐TiOPc‐NPs/insulator/Y‐TiOPc‐NPs quantum junctions exhibit outstanding xerographic properties by virtue of the high photogeneration quantum efficiency and high work function of the Y‐TiOPc‐NPs, as well as efficient light‐induced electron tunneling through the junctions.