Solid-state acoustoelectric light scanner

Light emitting p-n junctions are scanned by an acoustic domain traveling at sound velocity in CdS at room temperature. The light elements are heterojunctions formed by depositing p-Cu²S on n-CdS. The acoustic domain is generated in semiconducting CdS by applying a bias electric field which gives the electrons a drift velocity greater than the shear sound velocity. When the acoustic domain is in the vicinity of a p-n junction, part of the acoustic energy is transformed into light. As the domain travels between consecutive light elements it replenishes its lost acoustic energy from the bias electric field.