- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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What limits the efficiency of GaN-based superluminescent light-emitting diodes (SLEDs)?
摘要： Gallium-nitride-based SLEDs are attractive light sources for augmented reality displays and other applications. However, the electrical-to-optical power conversion efficiency (PCE) of SLEDs is still far below the record-high values reported for LEDs. Utilizing advanced numerical device simulation, this paper investigates the internal physical pro- cesses that cause the low PCE of SLEDs. The poor hole conductivity strongly reduces the electrical efficiency, similar to laser diodes. However, in contrast to laser diodes, the rising carrier density in the active layers is identified as main reason for enhanced Auger recom- bination that severely limits the internal quantum efficiency. Design improvement options are demonstrated.
关键词： Superluminescent light-emitting diode,Auger recombination,InGaN/GaN,Laser diode,Self-heating,Power conversion efficiency,SLED,Hole conductivity
更新于2025-09-12 10:27:22
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Study on the oxidation and release of gases in spontaneous coal combustion using a dual-species sensor employing laser absorption spectroscopy
摘要： Coal spontaneous combustion (CSC) is a common hazard in coal mines and a significant reason for the loss of coal in stockpiles and mines. To investigate the oxidation and release of gas due to of CSC, a miniature purpose-built laser-based sensor system capable of precise gas measurement and data processing was configured. A distributed feedback (DFB) diode laser with a central wavelength of 2.33 μm, in conjunction with a Herriot-type cell and wavelength modulation spectroscopy (WMS), was used for the simultaneous detection of methane (CH4) and carbon monoxide (CO) during coal combustion. The second-harmonic of WMS was applied to ensure sensor robustness and sensitivity with long-term performance for the system being evaluated by calculating the Allan-Werle deviations for the concentrations of CH4 and CO. The limits of detection (LoDs) for CH4 and CO were 0.05 ppm based on integration times of 120 s and 70 s, respectively. The dual-species sensor was employed for real-time and in situ investigations of coal samples for temperatures ranging from 85 °C to 200 °C and was considered suitable for integration into field monitoring equipment, especially for online early warning forecasting applications in CSC.
关键词： Wavelength modulation spectroscopy,Spontaneous coal combustion,Chemical inhibitor,Laser-based dual-species sensor,Self-heating oxidation
更新于2025-09-12 10:27:22
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Analysis on DC and AC Characteristics of Self Heating Effect in Nanowire
摘要： As devices are scaling down aggressively, three-dimensional field-effect transistors (FETs) becomes one of essential factors to obtain high gate controllability in order to reduce leakage current. However, insulators surrounding channel for above the reason block heat emission so that the lattice temperature can increase to the critical levels for devices. This phenomenon, called Self Heating Effect (SHE), can deteriorate device performance significantly. From this point of view, overall study on SHE in 5 nm node Nanowire FET (NWFET) was implemented by simulation. Through analysis on on-current (Ion), thermal resistance (Rth), transient characteristics, the DC and AC characteristics were investigated.
关键词： Thermal Resistance (Rth),Self Heating Effect (SHE),Nanowire FET (NWFET)
更新于2025-09-11 14:15:04
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Image distortion of working digital camera induced by environmental temperature and camera self-heating
摘要： We investigated image distortion induced by the coupling effect between the self-heating of a digital camera and environmental temperature, and then proposed a model to explain the relationship between environmental temperature and thermal-induced image distortion. First, we analyzed the heat transfer between the (self-heating) camera and the environment to elucidate the relationship between the environmental and camera-component temperatures. Next, we analyzed the thermal-induced change of imaging optical path to derive the relationship between the camera-component temperatures and image distortion. Finally, we established and verified a new model for thermal-induced image distortion. Our results indicate that camera-self-heating-induced image distortion forms a special case described by our model.
关键词： Camera self-heating,Digital camera,Image distortion error,Environmental temperature
更新于2025-09-10 09:29:36
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[IEEE 2018 14th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT) - Qingdao, China (2018.10.31-2018.11.3)] 2018 14th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT) - Simulation of a Novel Integrated 4H-SiC Temperature Sensor
摘要： This paper presents a novel integrated Schottky barrier diode temperature sensor in a 4H-SiC power MOSFET. Dual electrical isolation and additional current path are applied to this temperature sensor, allowing the sensor to work properly in any operating state of power MOSFET. Due to the sufficient electrical isolation, the crosstalk between sensor and power MOSFET is almost eliminated. Furthermore, high sensitivity S=1.21mV/K is observed for a constant bias current of Id=1mA. The temperature sensor exhibits a good degree of linearity with a root mean square error R2=0.99996.
关键词： Temperature sensor,4H-SiC,Power MOSFET,Self-heating,Crosstalk
更新于2025-09-04 15:30:14
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[IEEE 48th European Solid-State Device Research Conference (ESSDERC 2018) - Dresden (2018.9.3-2018.9.6)] 2018 48th European Solid-State Device Research Conference (ESSDERC) - Experimental extraction of BEOL composite equivalent thermal conductivities for application in self-heating simulations
摘要： Self-heating effects can seriously accelerate FEOL and BEOL degradation mechanisms. Moreover, as FET dimensions are continiously decreasing, the thermal resistance towards the Si bulk is increasing. As a result, the thermal properties of the BEOL become increasingly important. We develop dedicated test-structures and assess the equivalent thermal properties of the BEOL composite, which consists of Cu metallization and low-k interlayer dielectric (ILD). We study the impact of via density and configurations typical for those used in VLSI circuit designs. We can find through 3DFEM simulations, that equivalent anisotropic thermal properties can be provided for this composite, which can serve as calibrated parameters for FET thermal simulations.
关键词： BEOL,self-heating,thermal conductivity,FET,3DFEM simulations
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Short Circuit Ruggedness of New Generation 1.2 kV SiC MOSFETs
摘要： New generations of silicon carbide (SiC) based MOSFETs are commercially available from manufacturers featuring smaller chip size with higher power density demonstrating performance improvement compared to their previous generation counterparts. As the size of the chip is small, the volume available to dissipate energy during short-circuit (SC) like conditions is reduced, leading to increased self-heating of the device. Therefore, the short circuit withstand time (SCWT) is reduced. As a reliability aspect, ruggedness to extreme operating conditions like SC needs to be analyzed for these devices, to improve the design or to design better detection and protection circuits for these MOSFETs when used in specific SC vulnerable applications. In this work, the new third generation 1.2 kV SiC MOSFET from Wolfspeed in a TO-247-4 pin package having a smaller chip size is measured for SC ruggedness. The causes for device failure under different DC-link voltages, gate bias voltages, SC pulse durations and self-heating behavior are analyzed based on the destructive SC tests performed. The device is measured to have an SCWT of 2 μs at a DC-link voltage of 800 V compared to SCWT of 4.5 μs for the second generation 1.2 kV devices with larger chip size and TO-247-3 pin package. The presence of the Kelvin source contact demonstrates higher peak SC currents compared to the same devices without Kelvin source.
关键词： short-circuit ruggedness,SiC MOSFETs,Kelvin source contact,self-heating,failure analysis
更新于2025-09-04 15:30:14