Following the significant discovery of van der Waals (vdW) layered materials with diverse electronic properties over more than a decade ago, the scalable production of high-quality vdW layered materials has become a critical goal to enable the transformation of fundamental studies into practical applications in electronics. To this end, solution-based processing has been proposed as a promising technique to yield vdW layered materials in large quantities. Moreover, the resulting dispersions are compatible with cost-effective device fabrication processes such as inkjet printing and roll-to-roll manufacturing. Despite these advantages, earlier works on solution-based processing methods (i.e., direct liquid-phase exfoliation or alkali-metal intercalation) have several challenges in achieving high-performance electronic devices, such as structural polydispersity in thickness and lateral size or undesired phase transformation. These challenges hinder the utilization of the solution-processed materials in the limited fields of electronics such as electrodes and conductors. In the meantime, the groundbreaking discovery of another solution-based approach, molecular intercalation-based electrochemical exfoliation, has shown significant potential for the use of vdW layered materials in scalable electronics owing to the nearly ideal structure of the exfoliated samples. The resulting materials are highly monodispersed, atomically thin, and reasonably large, enabling the preparation of electronically active thin-film networks via successful vdW interface formation. The formation of vdW interfaces is highly important for efficient plane-to-plane charge transport and mechanical stability under various deformations, which are essential to high-performance, flexible electronics. In this Perspective, we survey the latest developments in solution-based processing of vdW layered materials and their electronic applications while also describing the field's future outlook in the context of its current challenges.
Sensor-based computing minimizes latency and energy consumption by processing data at the capture point, thereby eliminating extensive data transfer and enabling real-time decision-making. Here, we present a breakthrough in in-sensor computing via circularly polarized light detectors that integrate cholesteric liquid crystal reflectors with two-dimensional van der Waals p-n heterostructures. Our device exhibits a high dissymmetry factor (1.90), allowing effective separation of mixed circularly polarized images, along with a rapid photoresponse (4 μs) and wide linear dynamic range (up to 114.1 dB), suitable for analog multiply-and-accumulate operations in convolution-based in-sensor computing. Harnessing these detectors, we propose mixed-multimodal in-sensor computing using the chiral state of circularly polarized light to dynamically control responsivity, which enables the blending of two arbitrary image processing modes within a single, non-reconfigurable circuit. By effectively integrating polarization-sensitive detectors into the in-sensor computing framework, the proposed architecture preserves kernel optimization capabilities while simplifying circuit complexity.