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Inserting multiple quantum wells (MQWs) into a p–n junction, III-nitride MQW diodes can separately function as a light transmitter, modulator, and receiver under different bias conditions. Owing to the spectral overlap between the emission and responsivity spectra, the emitted light from the transmitter is able to be modulated and detected by the modulator and receiver, which have identical MQW structures. Here, we develop a compatible fabrication process to monolithically integrate an III-nitride light transmitter, waveguides, Y-splitter, modulators, Y-combiner, and receiver into a tiny chip. An on-chip 405 nm light communication system is established and exhibits a transmission rate of 260 Mbps in the non-return-to-zero on-off keying scheme. The results pave a feasible route to develop sophisticated monolithic photonic circuit on an III-nitride-on-silicon platform. [ABSTRACT FROM AUTHOR]

The integration of III‐nitride electronics and photonics is of great interest toward future computing systems with low power consumption. Multifunctioning multiple quantum well (MQW) diodes can address the challenging issue for on‐chip integration of a light source, which is a key component to drive the photonic circuits. Herein, a transmitter, waveguide, modulator, and receiver are monolithically integrated on a III‐nitride‐on‐silicon platform to perform light emission, transmission, modulation, and detection simultaneously. Both the receiver and modulator exhibit sufficient sensitivity to optical signals from the transmitter, which has an identical InGaN/AlGaN multiple quantum well (MQW) structure because the III‐nitride diode provides spectral overlap between the emission and absorption spectra. On‐chip data communication among these optical components is achieved using light, and the effective wavelength range is from 365 to 385 nm, in which multifunctional devices can be operated. [ABSTRACT FROM AUTHOR]

An on-chip optical interconnect of a light emitter, waveguide and photodetector based on p-n junction InGaN/GaN multiple quantum wells (MQWs) is fabricated to investigate the light coupling efficiency of suspended waveguides connecting the light emitter and photodetector. Optical characterizations indicate that the photocurrent of the photodetector is mainly induced by the emitted light that is transmitted through the waveguides. Suspended waveguides with and without air gaps are reported in this paper. A 1 mA current injection into the light emitter induces a photocurrent of 17.3 nA and 205.5 nA for the photodetector connected to the waveguides that with 10 μm air gaps and without air gaps, respectively. Finite-difference time-domain simulations are performed to analyze the gap effect on the coupling efficiency of the light transmission. Both the gap distance and the index variation of the gap materials are analyzed to verify the potential optical sensing functions of the on-chip optical interconnect. A possible strategy for increasing the light coupling efficiency is proven by simulations. [ABSTRACT FROM AUTHOR]

We propose a wafer-level procedure for the fabrication of 1.5-mm-diameter dual functioning InGaN/GaN multiple-quantum-well (MQW) diodes on a GaN-on-silicon platform for transferrable optoelectronics. Nitride semiconductor materials are grown on (111) silicon substrates with intermediate Al-composition step-graded buffer layers, and membrane-type MQW-diode architectures are obtained by a combination of silicon removal and III-nitride film backside thinning. Suspended MQW-diodes are directly transferred from silicon to foreign substrates such as metal, glass and polyethylene terephthalate by mechanically breaking the support beams. The transferred MQW-diodes display strong electroluminescence under current injection and photodetection under light irradiation. Interestingly, they demonstrate a simultaneous light-emitting light-detecting function, endowing the 1.5-mm-diameter MQW-diode with the capability of producing transferrable optoelectronics for adjustable displays, wearable optical sensors, multifunctional energy harvesting, flexible light communication and monolithic photonic circuit. [ABSTRACT FROM AUTHOR]

We propose and fabricate a comb-like light-induced synaptic transistor composed of two InGaN/GaN multiple-quantum-well diodes (MQWDs) with a common base. One InGaN/GaN MQWD is used as an emitter of light, and another InGaN/GaN MQWD is used as a collector. When a presynaptic voltage is applied to the emitter to generate light, the collector absorbs the emitted light and demonstrates an excitatory postsynaptic voltage (EPSV). Saturated EPSV behavior occurs at the collector when multiple pulse signals are continuously applied to the emitter. The saturated EPSV value is increased and the saturated pulse number is reduced as the amplitude of the applied pulse signal increases. Experimental results indicate that continuous stimuli with a high pulse intensity will greatly improve the memory effect during the learning process. [ABSTRACT FROM PUBLISHER]

We propose and fabricate a light induced transistor using a combination of two multiple-quantum-well diodes (MQWDs) with a common n-electrode as the base. Both silicon removal and back wafer etching are conducted to obtain a suspended device architecture. The InGaN/GaN MQWD detects light only when the bias voltage is below the turn-ON voltage and can simultaneously achieve light emission and detection when it turns ON. Therefore, the light induced transistor operates with two distinct light detection modes. The excitatory postsynaptic voltages (EPSVs) are distinct due to the different decay times. Paired-pulse facilitation is experimentally demonstrated to mimic the synaptic plasticity behavior. The EPSV amplitudes are dependent on the pulse interval and pulse number. [ABSTRACT FROM AUTHOR]

Here, we propose, fabricate and characterize the light manipulation of a suspended-membrane InGaN/GaN multiple-quantum-well light-emitting diode (MQW-LED) with a dielectric distributed Bragg reflector (DBR) positioned at the bottom, implemented on a GaN-on-silicon platform. Silicon removal is conducted to obtain the suspended MQW-LED architecture, and back wafer thinning of the epitaxial film is performed to improve the device performance. A 6-pair SiO 2 /Ta 2 O 5 DBR is deposited on the backside to manipulate the emitted light. The experimental results demonstrate that the bottom dielectric DBR exhibits high reflectivity and distinctly changes the light emission, which are consistent with the performed simulation results. This work represents a significant step towards the realization of inexpensive, electrically driven and simply fabricated GaN VCSELs for potential use in number of applications. [ABSTRACT FROM AUTHOR]

Here, we propose, fabricate and characterize suspended photonic integration of InGaN multiple-quantum-well light-emitting diode (MQW-LED), waveguide and InGaN MQW-photodetector on a single chip. The unique light emission property of InGaN MQW-LED makes it feasible to establish multi-dimensional spatial data transmission using visible light. The in-plane light communication system is comprised of InGaN MQW-LED, waveguide and InGaN MQW-photodetector, and the out-of-plane data transmission is realized by detecting the free-space light emission via a commercial photodiode module. Moreover, a full-duplex light communication is experimentally demonstrated at a data transmission rate of 50 Mbps when both InGaN MQW-diodes operate under simultaneous light emission and detection mode. The in-plane superimposed signals are able to be extracted through the self-interference cancellation method, and the out-of-plane superimposed signals are in good agreement with the calculated signals according to the extracted transmitted signals. These results are promising for the development of on-chip InGaN photonic integration for diverse applications. [ABSTRACT FROM AUTHOR]

We report here a membrane-type integration of InGaN/GaN multiple-quantum-well diodes (MQWDs) with a waveguide to build a highly integrated photonic system to perform functionalities on a GaN-on-silicon platform. Suspended MQWDs can be used as either for light-emitting diode (LED) or photodiode. In the fabricated photonic system, part of the LED emission is coupled into a suspended waveguide, and the guided light laterally propagates along the waveguide and is finally sensed by the photodiode. The photonic system can detect the in-plane guided light and the external incident light simultaneously. Planar optical communication experimentally demonstrates that the proof-of-concept monolithic photonic integration system can achieve the in-plane visible light communication. This work paves the way towards novel active electro-optical sensing systems and planar optical communication in the visible range. [ABSTRACT FROM AUTHOR]