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Quench rate dependence of center formation in Er implanted Si
Authors:
Mark A. Hughes,
Huan Liu,
Yaping Dan
Abstract:
Er implanted Si (Er:Si) is a promising candidate for scalable planar quantum memory (QM) applications. Er has a preference to coordinate with O impurities, and multiple types of Er center are typically formed after a post implant anneal. Float zone Si was implanted with 1018 cm-3 Er and separate samples were annealed using a rapid quench annealing technique at 950 degC for 10 min with quench rates…
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Er implanted Si (Er:Si) is a promising candidate for scalable planar quantum memory (QM) applications. Er has a preference to coordinate with O impurities, and multiple types of Er center are typically formed after a post implant anneal. Float zone Si was implanted with 1018 cm-3 Er and separate samples were annealed using a rapid quench annealing technique at 950 degC for 10 min with quench rates of 5, 23, 46, 93, 185 and 400 degC/s. The evolution of photoluminescence (PL) peaks and their associated Er centers was tracked as a function of quench rate. Across all samples, five distinct Er centers were identified. Two centers, one with mixed Si and O coordination and one with Si-only coordination, exhibited fully resolved crystal-field splitting of the 4I15/2 ground state together with 2 to 3 hot lines from the 4I13/2 excited state; fitting of crystal-field parameters for both was consistent with C2v symmetry. The mixed Si and O coordinated center was suppressed at quench rates above 185 degC/s, while the Si-only coordinated center was progressively enhanced with increasing quench rate up to the maximum of 400 degC/s. These results demonstrate that rapid quench annealing has the potential to selectively stabilize a single, Si-coordinated Er center in Er:Si, which is required for QM applications.
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Submitted 20 October, 2025;
originally announced October 2025.
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High-efficiency silicon LED with ultra-wideband emission from visible to infrared at room temperature
Authors:
Xiaobo Li,
Jiajing He,
Yaping Dan,
Jun Wang
Abstract:
The primary challenge in silicon photonics is achieving efficient luminescence in the communication band, crucial for its large-scale application. Despite significant efforts, silicon light sources still suffer from low efficiency and limited emission wavelengths. We addressed this by achieving broadband luminescence from 600-1650 nm through femtosecond laser annealing of 220nm standard SOI, resul…
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The primary challenge in silicon photonics is achieving efficient luminescence in the communication band, crucial for its large-scale application. Despite significant efforts, silicon light sources still suffer from low efficiency and limited emission wavelengths. We addressed this by achieving broadband luminescence from 600-1650 nm through femtosecond laser annealing of 220nm standard SOI, resulting in an external quantum efficiency exceeding 0.26% and an output optical power density greater than 20 W/cm2, several orders of magnitude higher than other silicon-based LEDs in performance. The broadband LED has potential applications in optical inspection, gas sensing, optical coherence tomography, optical communication, and more.
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Submitted 10 August, 2025;
originally announced August 2025.
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Photon emission gain in Er doped Si light emitting diodes by impact excitation
Authors:
Huayou Liu,
Jiayuan Zhao,
Jing Zhang,
Huan Liu,
Jiajing He,
Ulrich Kentsch,
Shengqiang Zhou,
Manfred Helm,
Yaping Dan
Abstract:
This work demonstrates photon emission gain, i.e., emission of multiple photons per injected electron, through impact excitation in Er-doped silicon light-emitting diodes (LEDs). Conventional methods for exciting Er ions in silicon suffer from low efficiency due to mismatched energy transfer between exciton recombination and Er excitation. Here, we propose a reverse-biased Si PN junction diode whe…
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This work demonstrates photon emission gain, i.e., emission of multiple photons per injected electron, through impact excitation in Er-doped silicon light-emitting diodes (LEDs). Conventional methods for exciting Er ions in silicon suffer from low efficiency due to mismatched energy transfer between exciton recombination and Er excitation. Here, we propose a reverse-biased Si PN junction diode where ballistically accelerated electrons induce inelastic collisions with Er ions, enabling tunable excitation via electric field modulation. Theoretical modeling reveals that photon emission gain arises from multiple impact excitations by a single electron traversing the electroluminescence region, with the gain value approximating the ratio of emission region width to electron mean free path, i.e., G = Lex/l. Experimental results show an internal quantum efficiency (IQE) of 1.84% at 78 K, representing a 20-fold enhancement over room-temperature performance. This work provides a critical foundation for on-chip integration of silicon-based communication-band lasers and quantum light sources.
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Submitted 23 May, 2025;
originally announced May 2025.
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Rapid quench annealing of Er implanted Si for quantum networking applications
Authors:
Mark A. Hughes,
Huan Liu,
Adam Brookfield,
Tianrui Wang,
Iain F. Crowe,
Yaping Dan
Abstract:
Erbium implanted silicon (Er:Si) is a promising platform for quantum networking applications, but a major obstacle is the formation of multiple Er centres. We show that the previously identified cubic centre (Er-C) has C2v or lower symmetry. Using crystal field analysis of Er-C and other Er centres, and by comparison with extended X-ray absorption fine structure (EXAFS) measurements, we show that…
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Erbium implanted silicon (Er:Si) is a promising platform for quantum networking applications, but a major obstacle is the formation of multiple Er centres. We show that the previously identified cubic centre (Er-C) has C2v or lower symmetry. Using crystal field analysis of Er-C and other Er centres, and by comparison with extended X-ray absorption fine structure (EXAFS) measurements, we show that Er centres can be arranged in a sequence, ranging from entirely Si coordinated, through mixed Si and oxygen (O) coordination, to entirely O coordinated. G-factors calculated from our crystal field fitting closely match those determined by Zeeman splitting and electron paramagnetic resonance (EPR) measurements. We co-implanted Si with Er and O (each to a concentration of 1019 cm-3). By increasing the quenching rate of the subsequent thermal anneal from ~100 °C/s to ~1000 °C/s, we change the dominant optically active centre, formed from Er2O3 clusters to the less energetically favourable Er-C centre with mixed Si and O coordination. Temperature dependent photoluminescence (PL) shows that Er2O3 clusters and Er-C centres have an O-related defect state at ~200 and 90 meV above the 4I13/2 Er manifold, respectively. PL lifetime measurements show that the Er2O3 clusters and Er-C centres fall into two or three classes, characterised by different non-radiative PL decay rates. Our high quench rate annealing process could facilitate the formation of a single, optically active Er centre, which is preferable for quantum networking applications of Er:Si.
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Submitted 18 August, 2024;
originally announced August 2024.
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High Performance MoS2 Phototransistors Photogated by PN Junction
Authors:
Seyed Saleh Mousavi Khaleghi,
Jianyong Wei,
Yumeng Liu,
Zhengfang Fan,
Kai Li,
Kenneth B. Crozier,
Yaping Dan
Abstract:
Photodetectors based on two-dimensional (2D) atomically thin semiconductors suffer from low light absorption, limiting their potential for practical applications. In this work, we demonstrate a high-performance MoS2 phototransistors by integrating few-layer MoS2 on a PN junction formed in a silicon (Si) substrate. The photovoltage created in the PN junction under light illumination electrically ga…
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Photodetectors based on two-dimensional (2D) atomically thin semiconductors suffer from low light absorption, limiting their potential for practical applications. In this work, we demonstrate a high-performance MoS2 phototransistors by integrating few-layer MoS2 on a PN junction formed in a silicon (Si) substrate. The photovoltage created in the PN junction under light illumination electrically gates the MoS2 channel, creating a strong photoresponse in MoS2. We present an analytical model for the photoresponse of our device and show that it is in good agreement with measured experimental photocurrent in MoS2 and photovoltage in the Si PN junction. This device structure separates light absorption and electrical response functions, which provides us an opportunity to design new types of photodetectors. For example, incorporating ferroelectric materials into the gate structure can produce a negative capacitance that boosts gate voltage, enabling low power, high sensitivity phototransistor; this, combined with separating light absorption and electrical functions, enables advanced high-performance photodetectors.
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Submitted 7 August, 2024;
originally announced August 2024.
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Analytical photoresponses of gated nanowire photoconductors
Authors:
Yinchu Shen,
Jiajing He,
Yang Xu,
Kaiyou Wang,
Yaping Dan
Abstract:
Low-dimensional photoconductors have extraordinarily high photoresponse and gain, which can be modulated by gate voltages as shown in literature. However, the physics of gate modulation remains elusive. In this work, we investigated the physics of gate modulation in silicon nanowire photoconductors with the analytical photoresponse equations. It was found that the impact of gate voltage varies vas…
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Low-dimensional photoconductors have extraordinarily high photoresponse and gain, which can be modulated by gate voltages as shown in literature. However, the physics of gate modulation remains elusive. In this work, we investigated the physics of gate modulation in silicon nanowire photoconductors with the analytical photoresponse equations. It was found that the impact of gate voltage varies vastly for nanowires with different size. For the wide nanowires that cannot be pinched off by high gate voltage, we found that the photoresponses are enhanced by at least one order of magnitude due to the gate-induced electric passivation. For narrow nanowires that starts with a pinched-off channel, the gate voltage has no electric passivation effect but increases the potential barrier between source and drain, resulting in a decrease in dark and photo current. For the nanowires with an intermediate size, the channel is continuous but can be pinched off by a high gate voltage. The photoresponsivity and photodetectivity is maximized during the transition from the continuous channel to the pinched-off one. This work provides important insights on how to design high-performance photoconductors.
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Submitted 2 April, 2024;
originally announced April 2024.
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Near-infrared and Mid-infrared Light Emission of Boron-doped Crystalline Silicon
Authors:
Xiaoming Wang,
Jiajing He,
Yaping Dan
Abstract:
The bottleneck in achieving fully integrated silicon photonics lies in silicon-based light-emitting devices that are compatible with standard CMOS technology. Dislocation loops by implanting boron into silicon and annealing represents an enticing strategy to transform highly inefficient silicon into a luminescent material. However, the emission at telecommunication wavelength suffers from the stro…
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The bottleneck in achieving fully integrated silicon photonics lies in silicon-based light-emitting devices that are compatible with standard CMOS technology. Dislocation loops by implanting boron into silicon and annealing represents an enticing strategy to transform highly inefficient silicon into a luminescent material. However, the emission at telecommunication wavelength suffers from the strong thermal quenching effect, resulting in low efficiency at room temperature. Here, we applied a new deep cooling process to address this issue. Interestingly, we find that electrons and holes recombine through defects emitting two photons, one in near infrared (NIR, 1.3~1.6 μm) and the other in mid-infrared band (MIR, around 3.5 μm). The PL intensity at NIR increases by three folds when the temperature increases from 77 K to 300K. Furthermore, the NIR light emission of reverse biased silicon diodes was significantly enhanced compared to forward bias, emitting the maximum output power of 42 nW at 60 mA. The results offer new opportunities for the development of IR light sources in integrated circuits.
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Submitted 18 January, 2024;
originally announced January 2024.
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Far-Field Super-Resolution Imaging By Nonlinear Excited Evanescent Waves
Authors:
Zhihao Zhou,
Wei Liu,
Jiajing He,
Lei Chen,
Xin Luo,
Dongyi Shen,
Jianjun Cao,
Yaping Dan,
Xianfeng Chen,
Wenjie Wan
Abstract:
Abbe's resolution limit, one of the best-known physical limitations, poses a great challenge for any wave systems in imaging, wave transport, and dynamics. Originally formulated in linear optics, this Abbe's limit can be broken using nonlinear optical interactions. Here we extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field, label-free, and scan-free super-res…
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Abbe's resolution limit, one of the best-known physical limitations, poses a great challenge for any wave systems in imaging, wave transport, and dynamics. Originally formulated in linear optics, this Abbe's limit can be broken using nonlinear optical interactions. Here we extend the Abbe theory into a nonlinear regime and experimentally demonstrate a far-field, label-free, and scan-free super-resolution imaging technique based on nonlinear four-wave mixing to retrieve near-field scattered evanescent waves, achieving sub-wavelength resolution of $λ/15.6$. This method paves the way for application in biomedical imaging, semiconductor metrology, and photolithography.
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Submitted 14 January, 2021;
originally announced January 2021.
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Stimulated emission at 1.54 $μ$m from Erbium/Oxygen-doped silicon-based light emitting diodes
Authors:
Jin Hong,
Huimin Wen,
Jiajing He,
Jingquan Liu,
Yaping Dan,
Jens W. Tomm,
Fangyu Yue,
Junhao Chu,
Chungang Duan
Abstract:
Silicon-based light sources including light-emitting diodes (LEDs) and laser diodes (LDs) for information transmission are urgently needed for developing monolithic integrated silicon photonics. Silicon doped by ion implantation with erbium ions (Er$^{3+}$) is considered a promising approach, but suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear em…
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Silicon-based light sources including light-emitting diodes (LEDs) and laser diodes (LDs) for information transmission are urgently needed for developing monolithic integrated silicon photonics. Silicon doped by ion implantation with erbium ions (Er$^{3+}$) is considered a promising approach, but suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear emission at 1.54 $μ$m from Er/O-doped silicon planar LEDs, which are produced by applying a new deep cooling process. Stimulated emission at room temperature is realized with a low threshold current of ~6 mA (~0.8 A/cm2). Time-resolved photoluminescence and photocurrent results disclose the complex carrier transfer dynamics from the silicon to Er3+ by relaxing electrons from the indirect conduction band of the silicon. This picture differs from the frequently-assumed energy transfer by electron-hole pair recombination of the silicon host. Moreover, the amplified emission from the LEDs is likely due to a quasi-continuous Er/O-related donor band created by the deep cooling technique. This work paves a way for fabricating superluminescent diodes or efficient LDs at communication wavelengths based on rare-earth doped silicon.
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Submitted 8 December, 2020;
originally announced December 2020.
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Programmable Multifunctional Plasmonic Waveguide System based on Coding Metamaterials and Inverse Design
Authors:
Yihang Dan,
Tian Zhang,
Jian Dai,
Kun Xu
Abstract:
In this article, we propose a programmable plasmonic waveguide system (PPWS) to achieve several different functions based on metal coding metamaterials (MCMs) and inverse design technology. There is no need to spend much time on considering the relation between the function and the structure because the MCMs in the PPWS are reprogrammable. In order to demonstrate the effectiveness of the PPWS, we…
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In this article, we propose a programmable plasmonic waveguide system (PPWS) to achieve several different functions based on metal coding metamaterials (MCMs) and inverse design technology. There is no need to spend much time on considering the relation between the function and the structure because the MCMs in the PPWS are reprogrammable. In order to demonstrate the effectiveness of the PPWS, we utilize it to achieve several filtering functions, including bandstop and bandpass filters. The simulation results exhibit that the performance of filters is improved based on genetic algorithm, particle swarm optimization, multi-traversal direct-binary search and simulated annealing. Especially, the bandwidth and quality factor for the narrow-band filter can reach 6.5 nm and 200.5. In addition to the simple filtering functions, some relatively complex transmission characteristics can be obtained by using the PPWS, such as plasmon-induced transparency-like effects. In conclusion, genetic algorithm is considered as the most efficient inverse design method for our system due to its less optimization time and stable performance. In comparison with the previous works, our proposed PPWS not only provides a general framework for obtaining an effective, flexible and compact plasmonic device but also shows the applications of inverse design on photonics devices.
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Submitted 2 January, 2021; v1 submitted 13 November, 2020;
originally announced November 2020.
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Efficient training and design of photonic neural network through neuroevolution
Authors:
Tian Zhang,
Jia Wang,
Yihang Dan,
Yuxiang Lanqiu,
Jian Dai,
Xu Han,
Xiaojuan Sun,
Kun Xu
Abstract:
Recently, optical neural networks (ONNs) integrated in photonic chips has received extensive attention because they are expected to implement the same pattern recognition tasks in the electronic platforms with high efficiency and low power consumption. However, the current lack of various learning algorithms to train the ONNs obstructs their further development. In this article, we propose a novel…
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Recently, optical neural networks (ONNs) integrated in photonic chips has received extensive attention because they are expected to implement the same pattern recognition tasks in the electronic platforms with high efficiency and low power consumption. However, the current lack of various learning algorithms to train the ONNs obstructs their further development. In this article, we propose a novel learning strategy based on neuroevolution to design and train the ONNs. Two typical neuroevolution algorithms are used to determine the hyper-parameters of the ONNs and to optimize the weights (phase shifters) in the connections. In order to demonstrate the effectiveness of the training algorithms, the trained ONNs are applied in the classification tasks for iris plants dataset, wine recognition dataset and modulation formats recognition. The calculated results exhibit that the training algorithms based on neuroevolution are competitive with other traditional learning algorithms on both accuracy and stability. Compared with previous works, we introduce an efficient training method for the ONNs and demonstrate their broad application prospects in pattern recognition, reinforcement learning and so on.
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Submitted 4 August, 2019;
originally announced August 2019.
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Machine learning and evolutionary algorithm studies of graphene metamaterials for optimized plasmon-induced transparency
Authors:
Tian Zhang,
Qi Liu,
Yihang Dan,
Shuai Yu,
Xu Han,
Jian Dai,
Kun Xu
Abstract:
Machine learning and optimization algorithms have been widely applied in the design and optimization for photonic devices. In this article, we briefly review recent progress of this field of research and show some data-driven applications (e.g. spectrum prediction, inverse design and performance optimization) for novel graphene metamaterials (GMs). The structure of the GMs is well-designed to achi…
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Machine learning and optimization algorithms have been widely applied in the design and optimization for photonic devices. In this article, we briefly review recent progress of this field of research and show some data-driven applications (e.g. spectrum prediction, inverse design and performance optimization) for novel graphene metamaterials (GMs). The structure of the GMs is well-designed to achieve the wideband plasmon induced transparency effect, which is regarded as optimization object and can be theoretically demonstrated by using transfer matrix method. Some classical machine learning algorithms, including k nearest neighbour, decision tree, random forest and artificial neural networks, are utilized to equivalently substitute the numerical simulation in the forward spectrum prediction and complete the inverse design for the GMs. The calculated results demonstrate that all the algorithms are effective and the random forest has advantages in terms of accuracy and training speed. Moreover, the single-objective and multi-objective optimization algorithms are used to achieve steep transmission characteristics by synthetically taking many performance metrics into consideration. The maximum difference between the transmission peaks and dips in the optimized transmission spectrum can reach 0.97. In comparison to previous works, we provide a guidance for intelligent design of photonic devices and advanced materials based on machine learning and evolutionary algorithms.
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Submitted 15 December, 2019; v1 submitted 4 August, 2019;
originally announced August 2019.
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Efficient Er/O Doped Silicon Light-Emitting Diodes at Communication Wavelength by Deep Cooling
Authors:
Huimin Wen,
Jiajing He,
Jin Hong,
Fangyu Yue,
Yaping Dan
Abstract:
A silicon light source at communication wavelength is the bottleneck for developing monolithically integrated silicon photonics. Doping silicon with erbium ions was believed to be one of the most promising approaches but suffers from the aggregation of erbium ions that are efficient non-radiative centers, formed during the standard rapid thermal treatment. Here, we apply a deep cooling process fol…
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A silicon light source at communication wavelength is the bottleneck for developing monolithically integrated silicon photonics. Doping silicon with erbium ions was believed to be one of the most promising approaches but suffers from the aggregation of erbium ions that are efficient non-radiative centers, formed during the standard rapid thermal treatment. Here, we apply a deep cooling process following the high-temperature annealing to suppress the aggregation of erbium ions by flushing with Helium gas cooled in liquid nitrogen. The resultant light emitting efficiency is increased to a record 14% at room temperature, two orders of magnitude higher than the sample treated by the standard rapid thermal annealing. The deep-cooling-processed Si samples were further made into light-emitting diodes. Bright electroluminescence with a spectral peak at 1.54 um from the silicon-based diodes was also observed at room temperature. With these results, it is promising to develop efficient silicon lasers at communication wavelength for the monolithically integrated silicon photonics.
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Submitted 22 January, 2019;
originally announced January 2019.
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Diffusion of Confidential Information on Networks
Authors:
Yuya Dan
Abstract:
This is a natural generalization of the previous work by Dan, "Modeling and Simulation of Diffusion Phenomena on Social Networks," to appear in The proceedings of 2011 Third International Conference on Computer Modeling and Simulation. In this paper, we consider the diffusion phenomena of personal or secret information on the variety of networks, such as complete, random, stochastic and scale-free…
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This is a natural generalization of the previous work by Dan, "Modeling and Simulation of Diffusion Phenomena on Social Networks," to appear in The proceedings of 2011 Third International Conference on Computer Modeling and Simulation. In this paper, we consider the diffusion phenomena of personal or secret information on the variety of networks, such as complete, random, stochastic and scale-free networks.
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Submitted 11 March, 2011; v1 submitted 1 January, 2011;
originally announced January 2011.