- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Infrared Light Management Using a Nanocrystalline Silicon Oxide Interlayer in Monolithic Perovskite/Silicon Heterojunction Tandem Solar Cells with Efficiency above 25%
摘要： Perovskite/silicon tandem solar cells are attractive for their potential for boosting cell efficiency beyond the crystalline silicon (Si) single-junction limit. However, the relatively large optical refractive index of Si, in comparison to that of transparent conducting oxides and perovskite absorber layers, results in significant reflection losses at the internal junction between the cells in monolithic (two-terminal) devices. Therefore, light management is crucial to improve photocurrent absorption in the Si bottom cell. Here it is shown that the infrared reflection losses in tandem cells processed on a flat silicon substrate can be significantly reduced by using an optical interlayer consisting of nanocrystalline silicon oxide. It is demonstrated that 110 nm thick interlayers with a refractive index of 2.6 (at 800 nm) result in 1.4 mA cm?2 current gain in the silicon bottom cell. Under AM1.5G irradiation, the champion 1 cm2 perovskite/silicon monolithic tandem cell exhibits a top cell + bottom cell total current density of 38.7 mA cm?2 and a certified stabilized power conversion efficiency of 25.2%.
关键词： monolithic perovskite/silicon tandem solar cells,infrared photocurrent absorption,nanocrystalline silicon oxide interlayers
更新于2025-10-22 19:40:53
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Novel method to measure the intrinsic spatial resolution in PET detectors based on monolithic crystals
摘要： The main aim of this work is to provide a method to retrieve the intrinsic spatial resolution of a gamma-ray detector block based on monolithic crystals within an assembled scanner. This method consists on a discrimination of the data using a software collimation process. The results are compared with an alternative method of separating two detector blocks far enough to produce a "virtual" source collimation due to the geometric constraints on the allowed coincidence event angles. A theoretical model has been deduced to fit the measured light distribution profiles, allowing estimating the detector intrinsic spatial resolution. The detector intrinsic spatial resolution is expected to follow a Gaussian distribution and the positron-emitter source shape, given the small size of a 22Na source with 0.25 mm in diameter, can be assumed to follow a Lorentzian profile. However, the collimation of the data modifies the source shape that is no longer a pure Lorentzian distribution. Therefore, the model is based on the convolution of a Gaussian shaped distribution (contribution of the detector) and a modified Lorentzian distribution (contribution of the collimated source profile) that takes into account the collimation effect. Three LYSO crystals geometries have been studied in the present work, namely a 10 mm thick trapezoidal monolithic block, and two rectangular monolithic blocks with thicknesses of 15 mm and 20 mm, respectively. All the blocks have size dimensions of 50 mm × 50 mm. The experimental results yielded an intrinsic detector spatial resolution of 0.64 ± 0.02 mm, 0.82 ± 0.02 and 1.07 ± 0.03 mm, for the 10 mm, 15 mm and 20 mm thick blocks, respectively, when the source was placed at the center of the detector. The detector intrinsic spatial resolution was moreover evaluated across one of the axis of each crystal. These values worsen to an average value of 0.68 ± 0.04 mm, 0.90 ± 0.14 and 1.29 ± 0.19 mm, respectively, when the whole crystal size is considered, as expected. These tests show an accurate method to determine the intrinsic spatial resolution of monolithic-based detector blocks, once assembled in the PET system.
关键词： Intrinsic spatial resolution,SiPM array,Monolithic blocks,Positron Emission Tomography,Gamma ray detectors
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A 300GHz Monolithic Integrated Amplifier in 0.5-μm InP Double Heterojunction Bipolar Transistor Technology
摘要： We present a compact, 6-stage terahertz monolithic integrated circuit (TMIC) amplifier with an operating frequency of 275-310GHz, formed by common-base configured 0.5 um InP Double Heterojunction Bipolar Transistor (DHBT) and a multilayer thin-film microstrip (TFM) wiring environment. The amplifier small signal gain exhibits >7.4dB at 300GHz. The peak gain is 12.5dB at 280GHz. This is the first time reported InP DHBT TMIC amplifier operating in H-band employing TFM in china. The total size of this 6-stage amplifier is only 1.7 mm ╳0.9 mm.
关键词： thin-film microstrip (TFM),Indium phosphide (InP),H-band,Amplifier,Heterojunction bipolar transistors (HBTs),Terahertz monolithic integrated circuit (TMIC)
更新于2025-09-23 15:22:29
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Monolithic integration of E/D-mode GaN MIS-HEMTs on ultrathin-barrier AlGaN/GaN heterostructure on Si substrates
摘要： Monolithically integrated enhancement/depletion-mode (E/D-mode) GaN-based metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) and inverters, were fabricated on an ultrathin-barrier (UTB) AlGaN/GaN heterostructure grown on Si substrates. By employing a graded AlGaN back barrier in the UTB-AlGaN/GaN heterostructure, a high threshold voltage (VTH) of +3.3 V is achieved in the E-mode MIS-HEMTs. The fabricated MIS-HEMT inverter features a high logic swing voltage of 7.76 V at a supply voltage of 8 V, a small VTH hysteresis as well as deviation less than 0.2 V. The UTB AlGaN/GaN-on-Si technology provides a good platform for integration of MIS-gate-based drivers and power transistors.
关键词： monolithic integration,ultrathin-barrier,GaN,E/D-mode,MIS-HEMT,inverter,AlGaN/GaN heterostructure,Si substrate
更新于2025-09-23 15:22:29
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Design of a Compact GaN MMIC Doherty Power Amplifier and System Level Analysis With X-Parameters for 5G Communications
摘要： This paper presents a monolithic microwave integrated circuit Doherty power amplifier (DPA) operating at sub-6 GHz for 5G communication applications by a 0.25-μm gallium nitride high-electron mobility transistor process. A compact impedance inverter and output matching of the DPA are achieved using a transmission line network and shunt capacitors. Also, the size ratio of power cells in the main and auxiliary amplifiers is optimized for a high efficiency at output power backoff (OPBO). The measured peak output power (Pout) and the 1-dB compression point (P1 dB) are 38.7 and 32.1 dBm, respectively, at 5.9 GHz. The power-added efficiency at 6-dB OPBO is up to 49.5%. Without digital predistortion (DPD), the DPA can deliver an average Pout of 23.5 dBm with error vector magnitude (EVM) <?28 dB and 21.5 dBm with EVM <?32 dB for 64-quadrature amplitude modulation (QAM) and 256-QAM signals, respectively. The measured X-parameters are employed to further investigate the DPA nonlinear characteristics and verify the accuracy of conventionally used power amplifier characterization/measurement methods for system-level design and testing applications. The simulated results based on the X-parameters also indicate that the average output power can be enhanced up to 25.7 dBm with DPD for 256-QAM.
关键词： 5G communication,monolithic microwave integrated circuit (MMIC),X-parameters,power-added efficiency (PAE),power amplifier (PA),Doherty,gallium nitride (GaN)
更新于2025-09-23 15:21:21
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Microwave behavior of a monolithic dual-wavelength DFB laser based on current injection model
摘要： A driving current based model describing the optical heterodyne output of a monolithic dual-wavelength DFB laser is established. The linear relationship between the driving current and the laser output wavelength was applied to obtain the simple equation for this purpose. Actual measured data from the real devices were used for the initial parameter extraction and the practical model can then be built. By using this model, the influence of different laser parameters towards the radio frequency signal generation and different current configuration on the output characteristic can be demonstrated. This can facilitate the future design of such integrated photonic devices.
关键词： Dual-wavelength,Distributed feedback (DFB) laser,Monolithic
更新于2025-09-23 15:21:01
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Nanoscale Light Sources for Optical Interconnects
摘要： This editorial is aimed at addressing two key aspects of nanoscale light sources: (1) low-power optical communication and (2) crystallographic defect engineering for monolithic integration with silicon. We will further discuss opportunities and challenges for nanoscale light sources for next generation, high density optical interconnect. Designing and prototyping light sources with sub light wavelength dimensions has been the topic of keen interest because of their versatility in optical communication. For example, nano light sources can operate at hundreds of GHz [1,2] which is not possible with conventional light sources [3]. In addition, power consumption in interconnects with these light sources can be reduced by omitting the modulator and using direct source modulation to encode optical data [4]. There are a number of nano light sources under investigation: (i) small photonic mode laser [5-9], (ii) plasmonic lasers [10,11] (iii) photonic-plasmonic hybrid lasers [12-15] and (iv) nanoscale LEDs [16,17]. Pros and cons of these nano light sources are discussed below.
关键词： crystallographic defect engineering,optical interconnects,low-power optical communication,Nanoscale light sources,monolithic integration
更新于2025-09-23 15:21:01
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Thermionic Emission-Based Interconnecting Layer Featuring Solvent Resistance for Monolithic Tandem Solar Cells with Solution-Processed Perovskites
摘要： All-perovskite tandem cells have been considered a potential candidate for bringing the power conversion efficiency (PCE) beyond the Shockley– Queisser limit of single-junction device while retaining the advantages of earth-abundant materials and solution processability. However, a challenging issue with regard to realizing such solution-processed devices is the fulfillment of complex and coupled requirements of the interconnecting layer (ICL), including solvent resistance to protect underlying perovskite film, high electrical properties for carrier transport and recombination, and high optical transmission. In this work, a new thermionic emission–based ICL with enhanced solvent resistance features is demonstrated. Fundamentally, the thermionic emission plays a critical role in the electron transport process in the ICL, which is confirmed through both experimental and theoretical studies. Besides achieving high optical transmission and electrical properties, the new ICL chemically protects the underlying perovskite film by introducing a fluoride silane– incorporated polyethylenimine ethoxylated hybrid system that also passivates the surface defects to reduce electrical loss. The monolithic all-perovskite tandem cells demonstrate highest PCE of 17.9% (from current density–voltage scan) and the highest steady-state efficiency is 16.1% for a typical device. Consequently, this work contributes to not only understanding the fundamental mechanism of ICLs but also promotes robust and low-cost photovoltaics.
关键词： monolithic all-perovskite tandem solar cells,solvent resistance,interconnecting layer,thermionic emission,defect passivation
更新于2025-09-23 15:21:01
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Characterization of a Low-Cost, Monolithically Integrated, Tunable 10G Transmitter for Wavelength Agile PONs
摘要： Dynamically reconfigurable passive optical networks (PONs) using time-division multiplexing and dense wavelength division multiplexing will require low-cost, high-performance customer premises equipment to be economically viable. In particular, substantial cost savings can be achieved through the use of efficient re-growth free, foundry-compatible fabrication techniques. Using this strategy, this paper presents the first detailed characterization of a monolithically integrated transmitter comprised of a discretely tunable slotted Fabry–Pérot ridge waveguide laser, an absorptive modulator and a semiconductor optical amplifier (SOA) produced using a standard off-the-shelf AlInGaAs/InP multiple quantum well epitaxial structure. This first generation device demonstrates a discrete single-mode tuning range of approximately 12 nm between 1551nm and 1563 nm with a side-mode suppression ratio ≥30 dB. Moreover, the integrated modulator section is shown to support transmission at 10 Gb/s using non-return to zero on-off keying with an extinction ratio in excess of 8 dB. Furthermore, using a time-resolved chirp measurement technique to examine dynamic deviations in the set carrier frequency, the modulator section exhibits a chirp contribution of <6 GHz using test patterns with high and low frequency content. In addition, the generation of optical bursts through the application of a gating function to the SOA section was found to shift the unmodulated carrier of a typical lasing mode by ≤8 GHz for gating periods comparable with a typical PON burst durations of 125 μs which are faster than the thermal response time of the transmitter material.
关键词： Optical communications,tunable semiconductor lasers,dense wavelength division multiplexing,passive optical networks,time division multiplexing,monolithic integration
更新于2025-09-23 15:21:01
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DEVELOPMENT OF AN EQUIVALENT CIRCUIT MODEL OF A FINITE GROUND COPLANAR WAVEGUIDE INTERCONNECT IN MIS SYSTEM FOR ULTRA-BROADBAND MONOLITHIC ICS
摘要： An equivalent circuit model of a ?nite ground plane coplanar waveguide (FGCPW) interconnect in a metal-insulator-semiconductor (MIS) system for an ultra-broadband monolithic IC is proposed and illustrated. An e?ective substrate considering Maxwell-Wagner Polarization is suggested and demonstrated. The method of modeling the weak skin e?ect of the conductor is presented. The accuracy of the equivalent circuit model is evaluated. This proposed FGCPW interconnect equivalent circuit model enables a quick and e?cient time domain simulation to estimate the time delay and bandwidth of ultra-broadband ICs.
关键词： FGCPW interconnect,MIS system,equivalent circuit model,weak skin effect,Maxwell-Wagner Polarization,ultra-broadband monolithic IC
更新于2025-09-23 15:19:57