In-memory photonic dot-product engine with electrically programmable weight banks.

Electronically reprogrammable photonic circuits based on phase-change chalcogenides present an avenue to resolve the von-Neumann bottleneck; however, implementation of such hybrid photonic-electronic processing has not achieved computational success. Here, we achieve this milestone by demonstrating an in-memory photonic-electronic dot-product engine, one that decouples electronic programming of phase-change materials (PCMs) and photonic computation. Specifically, we develop non-volatile electronically reprogrammable PCM memory cells with a record-high 4-bit weight encoding, the lowest energy consumption per unit modulation depth (1.

Electrochemically Quantifying the Phase Transition of Cesium Lead Halide Perovskite Quantum Dots in Purification.

A good purification strategy for obtaining high-quality and low-cost perovskite QDs ink requires a complete removal of the impurities but with a minimal phase transition of QDs from the perovskite phases to the nonperovskite δ-phase. This pioneering work reports the electrochemical quantification on the phase transition level of CsPbI QDs in purification. Cyclic voltammetry of the purified QDs evidenced the formation of a new product in the purification process, which was demonstrated to be the undesired nonperovskite δ-phase by independent structural analysis.