Monolithically integrated photonic chips with asymmetric MQWs structure for suppressing Stokes shift

An asymmetric (ASY) multiple quantum wells (MQWs) structure consisting of emission and detection regions with different In components and thicknesses is presented for suppressing the Stokes shift in monolithically integrated photonic chips. Compared with conventional MQWs, the total luminescence intensity of ASY MQWs is improved due to the action of the potential field for transferring more holes to the quantum well near the n-GaN side. Meanwhile, resulted from about 25–30 nm redshift in response spectra, a 4.5-fold increase in the overlap of luminescence-detection spectra is realized. A photodetector exhibits a photo-to-dark current ratio of up to 107 at 0 V bias. Furthermore, the reported ASY MQWs diode shows a maximum bandwidth (−3 dB) of 173 MHz, suggesting that a monolithically integrated chip has tremendous potential on the application of the on-chip visible light communication.