Spatial Audio Acquisition Using a Dual-Functioning MQW-Diode With a Three-Stage Amplifier Circuit

A multiple-quantum-well diode (MQW-diode) can function as a light-emitting diode or a photodiode. In particular, when appropriately biased, this dual-functioning device can simultaneously emit light and process information. Here, an MQW-diode of ring geometry is fabricated on a 1.64-mm-diameter suspended membrane by a combination of silicon separation and III-nitride backside thinning, and the 1.47-mm-diameter inner region enhances the overall light detection. When the MQW-diode operates under the simultaneous emission-detection mode, a three-stage amplifier circuit with a signal gain of 27.8 dB is used to recover the received signals, and the real-time spatial audio acquisition is experimentally demonstrated with the wire-bonded MQW-diode. This paper provides a promising path to produce multifunctional MQW-diodes toward the Internet of Things.