Characteristics of GaN-based LED fabricated on a GaN-on-silicon platform

Abstract

In this paper, we describe the fabrication and characterization of a GaN-based light-emitting diode (LED) on a GaN-on-silicon platform. A freestanding membrane structure eliminates the absorption of the emitted light by a silicon substrate and reduces the number of confined optical modes, leading to higher photoluminescence intensity. Compared with an LED with a silicon substrate, the current–voltage characteristics of a freestanding membrane LED demonstrate a lower turn-on voltage and a steeper current–voltage profile. Both anomalous positive capacitance peak and negative capacitance are observed in the capacitance–voltage measurements, which correspond well to the current–voltage characteristics. The measured electroluminescence intensity is significantly increased for a freestanding membrane LED. These experimental results show that our proposed substrate removal technology is promising for the fabrication of a high-performance membrane LED for diverse applications.