Developing high-performance organic photodetectors(OPDs)with spectral responses over 1000 nm is of paramount importance to fundamental research and practical applications,yet effective approaches to achieve this remai...Developing high-performance organic photodetectors(OPDs)with spectral responses over 1000 nm is of paramount importance to fundamental research and practical applications,yet effective approaches to achieve this remain elusive.Herein,we develop ultranarrow bandgap electron acceptors through a theory-guided synergistic modification strategy.The optimal electron acceptor shows absorption over 1100 nm with smaller reorganization energies,more regulated crystallinity with a predominant face-on packing mode,and better miscibility with polymer donors,which affords the resultant OPDs with improved charge dissociation and transport,and favorable active layer morphology.The optimized OPDs have less charge recombination,energetic disorder,and trap density,showing ultralow dark current density(Jd)of 3.8×10^(-11)A cm^(-2),high shot-noise-limited specific detectivities(D*sh)over 1013 Jones in the range of 320-1100 nm,and an ultrafast response time below 0.3μs.Further incorporating a fullerene derivative(PC71BM)as the third component suppresses Jd to 2.3×10^(-11)A cm^(-2),resulting in prominent D*sh values of over 10^(14)Jones spanning from 640 to 1020 nm,with a peak value of 1.4×10^(14)Jones at 950 nm.This work not only provides cutting-edge performance in near-infrared(NIR)OPDs reported so far but also opens an intriguing materialdriven dimension to achieve sensitive OPDs for vis-to-NIR broadband photodetection.展开更多
We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coup...We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coupling intensity of 2.3 W/cm^2, the filter shows a peak transmission of 33.2% and a bandwidth of 10 MHz. By altering the coupling frequency, a broad tuning range of several Doppler linewidths of the D1 line transitions of STRb atoms can be obtained. The presented atomic filter has useful features of ultranarrow bandwidth, and the operating frequency can be tuned resonance with the atomic transition. Such narrowband tunable atomic filter can be used as an efficient noise rejection tool in classical and quantum optical applications.展开更多
The absorption–dispersion properties of a microwave-driven five-level atom embedded in an isotropic photonic bandgap(PBG) have been studied. Due to the singular density of modes(DOM) in the isotropic PBG and the dyna...The absorption–dispersion properties of a microwave-driven five-level atom embedded in an isotropic photonic bandgap(PBG) have been studied. Due to the singular density of modes(DOM) in the isotropic PBG and the dynamically coherence induced by the coupling fields, modified reservoir-induced transparency and quantum interference-induced transparency emerge simultaneously. Their interaction leads to ultra-narrow spectral structure. As a result of closed-loop configuration, these features can be manipulated by the amplitudes and relative phase of the coherently driven fields. The position and width of PBG also have an influence on the spectra. The theoretical studies can provide us with more efficient methods to control the atomic absorption–dispersion properties, which have applications in optical switching and slow light.展开更多
基金the support from NSFC(grant nos.U21A20101,21875018,and 22305013)W.Liu also thanks the support from Fundamental Research Funds for the Central Universities(grant no.buctrc 202144).
文摘Developing high-performance organic photodetectors(OPDs)with spectral responses over 1000 nm is of paramount importance to fundamental research and practical applications,yet effective approaches to achieve this remain elusive.Herein,we develop ultranarrow bandgap electron acceptors through a theory-guided synergistic modification strategy.The optimal electron acceptor shows absorption over 1100 nm with smaller reorganization energies,more regulated crystallinity with a predominant face-on packing mode,and better miscibility with polymer donors,which affords the resultant OPDs with improved charge dissociation and transport,and favorable active layer morphology.The optimized OPDs have less charge recombination,energetic disorder,and trap density,showing ultralow dark current density(Jd)of 3.8×10^(-11)A cm^(-2),high shot-noise-limited specific detectivities(D*sh)over 1013 Jones in the range of 320-1100 nm,and an ultrafast response time below 0.3μs.Further incorporating a fullerene derivative(PC71BM)as the third component suppresses Jd to 2.3×10^(-11)A cm^(-2),resulting in prominent D*sh values of over 10^(14)Jones spanning from 640 to 1020 nm,with a peak value of 1.4×10^(14)Jones at 950 nm.This work not only provides cutting-edge performance in near-infrared(NIR)OPDs reported so far but also opens an intriguing materialdriven dimension to achieve sensitive OPDs for vis-to-NIR broadband photodetection.
基金supported by the National Basic Research Program of China(No.2006CB921203)the National Natural Science Foundation of China(No.11174327)+1 种基金the Foundation of Wuhan National Laboratory for Optoelectronics(No.P080002)the support of the Hundred Talent Program by the Chinese Academy of Sciences
文摘We report the experimental demonstration of an ultranarrow bandwidth atomic filter by optically induced polarization rotation in multilevel electromagnetically induced transparency systems in hot Rb vapor. With a coupling intensity of 2.3 W/cm^2, the filter shows a peak transmission of 33.2% and a bandwidth of 10 MHz. By altering the coupling frequency, a broad tuning range of several Doppler linewidths of the D1 line transitions of STRb atoms can be obtained. The presented atomic filter has useful features of ultranarrow bandwidth, and the operating frequency can be tuned resonance with the atomic transition. Such narrowband tunable atomic filter can be used as an efficient noise rejection tool in classical and quantum optical applications.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11447232 and 11204367)
文摘The absorption–dispersion properties of a microwave-driven five-level atom embedded in an isotropic photonic bandgap(PBG) have been studied. Due to the singular density of modes(DOM) in the isotropic PBG and the dynamically coherence induced by the coupling fields, modified reservoir-induced transparency and quantum interference-induced transparency emerge simultaneously. Their interaction leads to ultra-narrow spectral structure. As a result of closed-loop configuration, these features can be manipulated by the amplitudes and relative phase of the coherently driven fields. The position and width of PBG also have an influence on the spectra. The theoretical studies can provide us with more efficient methods to control the atomic absorption–dispersion properties, which have applications in optical switching and slow light.
基金The National Natural Science Foundation of China(No.61378037)the Fundamental Research Funds for the Central Universities(Nos.JUSRP51628B,1142050205180920)the Projects of International Cooperation and Exchanges NSFC(Nos.61511130508,61611130128)
