Light-Driven Permanent Charge Separation across a Hybrid Zero-Dimensional/Two-Dimensional Interface

We report the first demonstration of light-driven permanent charge separation across an ultrathin solid-state zero-dimensional (0D)/2D hybrid interface by coupling photoactive Sn-doped In₂O₃ nanocrystals with monolayer MoS₂, the latter serving as a hole collector. We demonstrate that the nanocrystals in this device-ready architecture act as local light-controlled charge sources by quasi-permanently donating ∼5 holes per nanocrystal to the monolayer MoS₂. The amount of photoinduced contactless charge transfer to the monolayer MoS₂ competes with what is reached in electrostatically gated devices. Thus, we have constructed a hybrid bilayer structure in which the electrons and holes are separated into two different solid-state materials. The temporal evolution of the local doping levels of the monolayer MoS₂ follows a capacitive charging model with effective total capacitances in the femtofarad regime and areal capacitances in the μF cm–² range. This analysis indicates that the 0D/2D hybrid system may be able to store light energy at densities of at least μJ cm–², presenting new potential foundational building blocks for next-generation nanodevices that can remotely control local charge density, power miniaturized circuitry, and harvest and store optical energy.