Hopping‐Mediated Zero‐Bias Photocharge Retention in Solution‐Processed Van Der Waals Heterostructures

Solution-processed two-dimensional semiconductors offer a scalable route to flexible optoelectronic devices, yet when restacked nanosheet films are assembled into heterostructures, their intrinsic disorder, hopping-dominated transport and heterogeneous interfaces are expected to limit ideal junction behavior. Here we show that liquid–liquid interface assembly of electrochemically exfoliated n-type MoS2 and p-type WSe2 yields nanometer-thick, centimeter-scale type-II heterostructures directly on paper substrates, translating disordered nanosheet films into macroscopic rectifying p–n junction networks. Under white-light illumination, these networks enter a long-lived photocharged state that persists for about 15 min at zero applied bias, demonstrating that the heterostructure itself can stabilize photocharge without a continuously applied voltage. Electrical measurements, terahertz spectroscopy and geometric hopping simulations show that this retention arises from transport-limited recombination, in which separated carriers relax through sparse electronically active pathways in the disordered nanosheet network. The stored charge is electrically accessible and can be released on demand through an external circuit to power a load or erased by a voltage pulse. These findings establish structural disorder as a tool for controlling recombination and photocharge dynamics in solution-processed van der Waals heterostructures, paving the way for scalable optoelectronic platforms that integrate light harvesting, charge storage, and controlled release.