High-Resolution Light-Emitting Diode Array Based on an Ordered ZnO Nanowire/SiGe Heterojunction

A high-resolution light-emitting diode (LED) array based on an ordered n-type ZnO nanowire/p-type SiGe heterojunction is proposed. The pixel pitch of the LED array is about 15 μm, corresponding to a pixel density of 1693 dpi. The fabrication and characterizations of the developed LED device are analyzed in detail. The results show that the electroluminescence (EL) emission of this LED device is mainly in the infrared range, which is dominated by the band gap of the SiGe alloy. Furthermore, a weak EL emission in the visible range can also be observed, and the enhanced light emission is demonstrated by the externally applied compressive strain using a patterned sapphire mold. In addition, the feasibility of implementing GeSn alloys in the developed LED structure is discussed.