Experimental Demonstration and Theoretical Analysis of Simultaneous Emission–Detection Phenomenon

[Image: see text] The demand for on-chip multifunctional optoelectronic systems is increasing in the Internet-of-Things era. Spectral emission–detection overlap endows an InGaN/GaN quantum well diode (QWD) with an intriguing capability to detect and modulate light emitted by itself, which is of great interest when merging electronics and photonics together on a single chip for the development of advanced information systems. When biased and illuminated at approximately the same time, the InGaN/GaN QWD can achieve light emission and detection simultaneously. Herein, we experimentally demonstrate the simultaneous emission–detection phenomenon and analyze the irreversibility of spectral emission–detection overlap according to energy diagram theory, which may answer why the QWD can only detect and modulate higher-energy photons than those emitted by itself.