The development of an efficient group-IV light source that is compatible with the CMOS process remains a significant goal in Si-based photonics.Recently,the Ge Sn alloy has been identified as a promising candidate for...The development of an efficient group-IV light source that is compatible with the CMOS process remains a significant goal in Si-based photonics.Recently,the Ge Sn alloy has been identified as a promising candidate for realizing Si-based light sources.However,previous research suffered from a small wafer size,limiting the throughput and yield.To overcome this challenge,we report the successful growth of Ge Sn/Ge multiple-quantum-well(MQW)p-i-n LEDs on a 12-inch(300-mm)Si substrate.To the best of our knowledge,this represents the first report of semiconductor LEDs grown on such a large substrate.The MQW LED epitaxial layer is deposited on a 12-inch(300-mm)(001)-oriented intrinsic Si substrate using commercial reduced pressure chemical vapor deposition.To mitigate the detrimental effects of threading dislocation densities on luminescence,the Ge Sn/Ge is grown pseudomorphically.Owing to the high crystal quality and more directness in the bandgap,enhanced electroluminescence(EL)integrated intensity of 27.58 times is demonstrated compared to the Ge LED.The MQW LEDs exhibit EL emission near 2μm over a wide operating temperature range of 300 to 450 K,indicating hightemperature stability.This work shows that Ge Sn/Ge MQW emitters are potential group-IV light sources for large-scale manufacturing.展开更多
To achieve high quality lighting and visible light communication(VLC)simultaneously,Ga N based white light emitting diodes(WLEDs)oriented for lighting in VLC has attracted great interest.However,the overall bandwidth ...To achieve high quality lighting and visible light communication(VLC)simultaneously,Ga N based white light emitting diodes(WLEDs)oriented for lighting in VLC has attracted great interest.However,the overall bandwidth of conventional phosphor converted WLEDs is limited by the long lifetime of phosphor,the slow Stokes transfer process,the resistance-capacitance(RC)time delay,and the quantum-confined Stark effect(QCSE).Here by adopting a self-assembled In Ga N quantum dots(QDs)structure,we have fabricated phosphor-free single chip WLEDs with tunable correlated color temperature(CCT,from 1600 K to 6000 K),a broadband spectrum,a moderate color rendering index(CRI)of 75,and a significantly improved modulation bandwidth(maximum of150 MHz)at a low current density of 72 A∕cm^2.The broadband spectrum and high modulation bandwidth are ascribed to the capture of carriers by different localized states of In Ga N QDs with alleviative QCSE as compared to the traditional In Ga N/Ga N quantum well(QW)structures.We believe the approach reported in this work will find its potential application in Ga N WLEDs and advance the development of semiconductor lighting-communication integration.展开更多
Commercial white LEDs (WLEDs) are generally limited in modulation bandwidth due to a slow Stokes process,long lifetime of phosphors,and the quantum-confined Stark effect. Here we report what we believe is a novel plas...Commercial white LEDs (WLEDs) are generally limited in modulation bandwidth due to a slow Stokes process,long lifetime of phosphors,and the quantum-confined Stark effect. Here we report what we believe is a novel plasmonic WLED by infiltrating a nanohole LED (H-LED) with quantum dots (QDs) and Ag nanoparticles(NPs) together (M-LED). This decreased distance between quantum wells and QDs would open an extra non-radiative energy transfer channel and thus enhance Stokes transfer efficiency. The presence of Ag NPs enhances the spontaneous emission rate significantly. Compared to an H-LED filled with QDs (QD-LED),the optimized M-LED demonstrates a maximum color rendering index of 91.2,a 43% increase in optical power at 60 m A,and a lowered correlated color temperature. Simultaneously,the M-LED exhibits a data rate of 2.21 Gb/s at low current density of 96 A∕cm2(60 m A),which is 77% higher than that of a QD-LED. This is mainly due to the higher optical power and modulation bandwidth of the M-LED under the influence of plasmon,resulting in a higher data rate and higher signal-to-noise ratio under the forward error correction.We believe the approach reported in this work should contribute to a WLED light source with increased modulation bandwidth for a higher speed visible light communication application.展开更多
基金CAS Project for Young Scientists in Basic Research(YSBR-026)National Research Foundation Singapore under its Competitive Research Program(NRFCRP19-2017-01)+1 种基金Ministry of Education-Singapore Ac RF Tier 2(T2EP50121-0001(MOE-000180-01))Ministry of Education-Singapore Ac RF Tier 1(2021-T1-002-031(RG112/21))。
文摘The development of an efficient group-IV light source that is compatible with the CMOS process remains a significant goal in Si-based photonics.Recently,the Ge Sn alloy has been identified as a promising candidate for realizing Si-based light sources.However,previous research suffered from a small wafer size,limiting the throughput and yield.To overcome this challenge,we report the successful growth of Ge Sn/Ge multiple-quantum-well(MQW)p-i-n LEDs on a 12-inch(300-mm)Si substrate.To the best of our knowledge,this represents the first report of semiconductor LEDs grown on such a large substrate.The MQW LED epitaxial layer is deposited on a 12-inch(300-mm)(001)-oriented intrinsic Si substrate using commercial reduced pressure chemical vapor deposition.To mitigate the detrimental effects of threading dislocation densities on luminescence,the Ge Sn/Ge is grown pseudomorphically.Owing to the high crystal quality and more directness in the bandgap,enhanced electroluminescence(EL)integrated intensity of 27.58 times is demonstrated compared to the Ge LED.The MQW LEDs exhibit EL emission near 2μm over a wide operating temperature range of 300 to 450 K,indicating hightemperature stability.This work shows that Ge Sn/Ge MQW emitters are potential group-IV light sources for large-scale manufacturing.
基金National Key Research and Development Program of China(2018YFB0406702)Professorship Startup Funding(217056)+2 种基金Innovation-Driven Project of Central South University,China(2018CX001)Project of State Key Laboratory of High-Performance Complex Manufacturing,Central South University,China(ZZYJKT2018-01)Fundamental Research Funds for the Central Universities of Central South University(2018zzts147)。
文摘To achieve high quality lighting and visible light communication(VLC)simultaneously,Ga N based white light emitting diodes(WLEDs)oriented for lighting in VLC has attracted great interest.However,the overall bandwidth of conventional phosphor converted WLEDs is limited by the long lifetime of phosphor,the slow Stokes transfer process,the resistance-capacitance(RC)time delay,and the quantum-confined Stark effect(QCSE).Here by adopting a self-assembled In Ga N quantum dots(QDs)structure,we have fabricated phosphor-free single chip WLEDs with tunable correlated color temperature(CCT,from 1600 K to 6000 K),a broadband spectrum,a moderate color rendering index(CRI)of 75,and a significantly improved modulation bandwidth(maximum of150 MHz)at a low current density of 72 A∕cm^2.The broadband spectrum and high modulation bandwidth are ascribed to the capture of carriers by different localized states of In Ga N QDs with alleviative QCSE as compared to the traditional In Ga N/Ga N quantum well(QW)structures.We believe the approach reported in this work will find its potential application in Ga N WLEDs and advance the development of semiconductor lighting-communication integration.
基金National Key Research and Development Program of China (2018YFB0406702)National Natural Science Foundation of China (61925104)+1 种基金Key Laboratory of Energy Conversion and Storage Technologies (Southern University of Science and Technology),Ministry of Education,ShenzhenFundamental Research Funds for the Central Universities of Central South University (2018zzts147)。
文摘Commercial white LEDs (WLEDs) are generally limited in modulation bandwidth due to a slow Stokes process,long lifetime of phosphors,and the quantum-confined Stark effect. Here we report what we believe is a novel plasmonic WLED by infiltrating a nanohole LED (H-LED) with quantum dots (QDs) and Ag nanoparticles(NPs) together (M-LED). This decreased distance between quantum wells and QDs would open an extra non-radiative energy transfer channel and thus enhance Stokes transfer efficiency. The presence of Ag NPs enhances the spontaneous emission rate significantly. Compared to an H-LED filled with QDs (QD-LED),the optimized M-LED demonstrates a maximum color rendering index of 91.2,a 43% increase in optical power at 60 m A,and a lowered correlated color temperature. Simultaneously,the M-LED exhibits a data rate of 2.21 Gb/s at low current density of 96 A∕cm2(60 m A),which is 77% higher than that of a QD-LED. This is mainly due to the higher optical power and modulation bandwidth of the M-LED under the influence of plasmon,resulting in a higher data rate and higher signal-to-noise ratio under the forward error correction.We believe the approach reported in this work should contribute to a WLED light source with increased modulation bandwidth for a higher speed visible light communication application.
