RESEARCH HlGHLlGHTS

1. The degradation of perovskite precursor
2. The voltage loss in organic solar cells

COMMENTS AND OPlNlONS

1. Moiré heterostructures: highly tunable platforms for quantum simulation and future computing

NEWS AND VlEWS

1. Single photon emitters originating from donor-acceptor pairs

EDlTORlAL

1. Preface to Special Topic on Twisted van der Waals Heterostructures

REVlEWS

1. Interface engineering in two-dimensional heterostructures towards novel emitters
2. The twisted two-dimensional ferroelectrics
3. Recent progress on fabrication and flat-band physics in 2D transition metal dichalcogenides moiré superlattices
4. Review of phonons in moiré superlattices
5. Interaction of moiré excitons with cavity photons in twodimensional semiconductor hetero-bilayers

ARTlCLES

1. Gate tunable spatial accumulation of valley-spin in chemical vapor deposition grown 40°-twisted bilayer WS2
2. 75 GHz germanium waveguide photodetector with 64 Gbps data rates utilizing an inductive-gain-peaking technique
3. Electromechanical and photoelectric properties of a novel semiconducting Janus InGaSSe monolayer