{"title":"Fast Pupil center localization system based on SSD Cascade gradient","authors":"Zilin Xun, Yuandong Gu, A. Guo, Fei Wang","doi":"10.1109/SSLChinaIFWS54608.2021.9675166","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675166","url":null,"abstract":"In order to solve the problem of low recognition and high misrecognition of traditional eye tracking system, which uses cascade classifier to obtain face image. This paper proposes a model of SSD(Single Shot MultiBox Detector) combined gradient algorithm. The method, firstly, put the SSD in depth study of facial model to replace the cascade classifier, with a face image segmentation the eye part of the detected image. Secondly using the improved gradient localization algorithm to locate the pupil center position, and then through the proposed simple judgment mechanism on the rationality of the pupil center again decrease the misrecognition, finally get the pupil center. Experimental results show that the proposed algorithm can achieve a detection rate of 5.42 frames per second and improve the detection accuracy by 6%.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"467 1","pages":"118-121"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77046050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. An, Kailin Ren, Xueying Xiu, Zebin Xu, Zhuang Wu, Luqiao Yin, Jianhua Zhang
{"title":"A Novel Monolithically Integrated Structure of GaN-based Micro-LED and its Driver HEMT","authors":"Y. An, Kailin Ren, Xueying Xiu, Zebin Xu, Zhuang Wu, Luqiao Yin, Jianhua Zhang","doi":"10.1109/SSLChinaIFWS54608.2021.9675206","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675206","url":null,"abstract":"In this work, a novel LED-HEMT integrated device structure with a p-GaN cap layer under the drain electrode of HEMT and one or more InGaN layers inserted between AlGaN/GaN is proposed for the monolithic integration of GaN-based Micro-LED and its driver HEMT. This structure is a promising candidate for the optoelectronic switch in high-speed visible light communications owing to its elimination of metal-interconnects and reduction of parasitic capacitance. By TCAD simulations, the distribution of radiative recombination rate in this structure is investigated and the 2-D integrals of the radiative recombination rate for various device structure designs are compared. It is concluded that the integration structure with InGaN layers provides higher radiative recombination than that without InGaN layers. Device structure parameters are optimized, including Al content in AlGaN barrier layer, In content in InGaN layers, and thickness of InGaN layers.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"14 1","pages":"150-153"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86921457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improvement of Interfacial Properties of 4H-SiC/SiO2 by Nitrogen Plasma Treatment","authors":"Guangrong Li, Xian Zou, Weiping Wang, Yongqiang Sun, Xu Li, Yaping Wu, Zhiming Wu, Junyong Kang","doi":"10.1109/SSLChinaIFWS54608.2021.9675178","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675178","url":null,"abstract":"In this work, the effect of nitrogen plasma treatment and post-deposition annealing (PDA) on the interfacial properties of 4H-SiC/SiO<inf>2</inf> were studied. The results showed that both nitrogen plasma treatment and PDA could reduce interface trap density (D<inf>it</inf>), and a minimal D<inf>it</inf> of 1.30×10<sup>11</sup> cm<sup>−2</sup>eV<sup>−1</sup> at 0.5 eV below 4H-SiC conduction band was obtained. Based on the characterization of X-ray photoelectron spectroscopy (XPS) and theoretical calculation, it is found that nitrogen plasma treatment, on one hand, can remove the surficial by-product of SiO<inf>x</inf>C<inf>y</inf>, and on the other hand, result in the passivation of interfacial dangling bonds and the formation of Si≡N, which contribute to the reduction of D<inf>it</inf>. This work provides a guidance for the development of high-performance 4H-SiC power devices.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"29 1","pages":"13-16"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82770786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Interpretation of the psychophysical results on preferred CCT and Duv when investigating colour preference of lighting","authors":"Zhiyu Chen, Pengzhi Zou, Xinwei Wu, Qiang Liu","doi":"10.1109/SSLChinaIFWS54608.2021.9675155","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675155","url":null,"abstract":"In this paper, the authors discuss a hot and disputable topic in colour quality evaluation for lighting. During the past years, it is quite common to investigate the impact of CCT and Duv on colour preference of lighting. Theoretically speaking, the conclusions of those work are not perfectly rigorous. First, there are numerous SPDs corresponding to a same CCT or Duv so counter-examples could always be raised. Second, most studies did not control colour rendition properties (quantified by colour quality metrics) of the experimental lights, thus it was not reasonable to solely ascribe the difference of visual perception to the impact of CCT or Duv. With the aim of comprehensively interpreting the rationality and limitations of those research, in this work we critically reviewed several typical studies and analyzed the correlation between CCT/Duv and 25 colour quality metrics. The result shows that although the experimental settings and protocols of current studies are diverse, in general their conclusions of preferred CCT/Duv are consistent. Such conclusion indicates that for practical use CCT and Duv could be regarded as effective indicators for evaluating colour preference because of the significant correlation between those measures and certain colour quality metrics.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"1 1","pages":"177-179"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90292747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Fu, Shujun Deng, Liang Wang, Hongjian Liao, J Zhang
{"title":"The negative impact of excessive vanadium doping for SiC crystal growth","authors":"F. Fu, Shujun Deng, Liang Wang, Hongjian Liao, J Zhang","doi":"10.1109/SSLChinaIFWS54608.2021.9675239","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675239","url":null,"abstract":"The effect of heavy vanadium doping on the growth of SiC single crystal was investigated. Pyramidal and cubic vanadium precipitates were discovered on the as-grown surface by DIC microscope. Further observation by AFM and SEM shows that the original parallel growth steps are twisted due to the blockage of vanadium precipitates, forming a triangular stepped flow with vanadium precipitates as the vertex. The results of secondary ion energy spectroscopy show that the doping amount of vanadium is close to its saturated solubility in SiC.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"77 1","pages":"68-70"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90837180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Structure optimization and fabrication of GaN quasi-vertical diode","authors":"Hao Guo, Weiling Guo, Yuxia Feng, Haijuan Cheng, Jiaxin Chen, Xiucheng Xu, Zhaoqiang Bai","doi":"10.1109/SSLChinaIFWS54608.2021.9675201","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675201","url":null,"abstract":"In order to improve the performance of GaN-on-Si quasi-vertical diodes, this letter demonstrates GaN quasi-vertical diodes with different anode area, the anode-cathode spacing (Lac) and layout design of electrodes (circular and finger type). By optimizing the fabrication process, the specific contact resistivity of ohmic contact between metal electrodes and n-GaN (ND~1×1019cm−3) is 3.38×10−5Ω.cm2. Comparing devices with different structures shows that the forward current density of the diodes increases with the decrease of the anode area. The increase of anode-cathode spacing leads to the increase of on-resistance. The forward J-V characteristics of the PN diodes with circular and finger-type anode are compared, the forward current density of the finger-type diode is larger than that of the circular type diode. By optimizing the device structure, a circular GaN quasi-vertical diode with the turn-on voltage of 3.2V (@1A/cm2), the specific on-resistance of 0.97mΩ.cm−2 and the on/off current ratio of 109 was obtained.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"144 1","pages":"45-48"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80408527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pingjuan Niu, Hao Sun, Liu Zhaofeng, Liu Qiang, Cao Shinan, Tian Haitao
{"title":"Design And Force Analysis of The Chip Transfer Platform for Mass Transfer","authors":"Pingjuan Niu, Hao Sun, Liu Zhaofeng, Liu Qiang, Cao Shinan, Tian Haitao","doi":"10.1109/SSLChinaIFWS54608.2021.9675200","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675200","url":null,"abstract":"Micro LED is a new generation displays with the fast response, low power consumption, high reliability and long life. The main process for the manufacture of the Micro LED is the transfer the Micro LED chips to the circuit boards. To improve the speed of the mass transfer, a Micro LED chips transfer platform was designed and the detailed description of the platforms work is presented. A 3D view of the platform is created, Than a analysis of the deformation of the chip carrier board during platform operation was been carried out. The result shows that the new platform can guarantee the deformation of the chips and the mass transfer speed can be improved as no need of the swing arm.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"18 1","pages":"143-145"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78392033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Congshan Dai, Nuoyi Li, Ali Hassan Shah, Jack Chen, Susan Chen, Shu Yi, Yandan Lin
{"title":"The effect of daylight LED on daytime cortisol concentration","authors":"Congshan Dai, Nuoyi Li, Ali Hassan Shah, Jack Chen, Susan Chen, Shu Yi, Yandan Lin","doi":"10.1109/SSLChinaIFWS54608.2021.9675196","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675196","url":null,"abstract":"The lack of sunlight in modern people may have adverse effects on physical and mental health. As a possible way to supply daylight exposure, daylight LED has attracted people's attention for its continuous and complete spectrum. This study compared the effect of daylight LEDs and LEDs with high color rendering index on cortisol secretion, which reflecting human alertness and circadian rhythm. The mean cortisol concentration of daylight LEDs at both CCTs was higher than that of normal LEDs. However, there are no significant effects when analyzing with change value.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"480 1","pages":"191-193"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77047557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vertical Illuminance Uniformity for LED Road Lighting","authors":"D. Lou, Yingdong Wei","doi":"10.1109/SSLChinaIFWS54608.2021.9675282","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675282","url":null,"abstract":"LED road lighting has been installed in many cities and it's dominating for almost all new roads. Its advantages have been well recognized, such as improved energy efficiency, better beam control, slim design, smart control, etc. However, visual discomfort has been one of the often-heard complaints about LED road lights since very long ago. Visual discomfort can be attributed to three factors in general: disability/discomfort glare, road surface uniformity, vertical illuminance distribution. For disability/discomfort glare and road surface uniformity, there have been abundant studies and standards available for engineers and researchers to refer to. While in comparison, the vertical illuminance distribution lacks sufficient investigative efforts. Of the many factors that impact visual comfort for road lighting, vertical illuminance distribution was sometimes mentioned but only in a qualitative manner and always linked with Small Target Visibility (STV). In this study, we aimed to fully understand the role of vertical illuminance distribution in visual comfort for road lighting. The related on-site investigations, perception tests, optical simulations, as well as the posterior verifications were all carried out on the context of typical China's road configurations. As a result, an initial model has been developed in characterizing the impact of vertical illuminance distribution on visual comfort for drivers. It is believed to be a proper supplement to the existing visual comfort evaluation system.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"260 1","pages":"180-183"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91030932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of Electrical Performances for a Two-Terminal Integrated PV-TE System","authors":"Jiaying Chen, Qinghao Zeng, Xi Deng, Guoqiang Li","doi":"10.1109/SSLChinaIFWS54608.2021.9675240","DOIUrl":"https://doi.org/10.1109/SSLChinaIFWS54608.2021.9675240","url":null,"abstract":"Photovoltaic (PV) cell absorbs sunlight and converts a part of solar energy into electricity. However, more than 60% of solar energy is converted to thermal energy, causing heating of the PV cell. Coupling a thermoelectric (TE) with a PV cell will utilize the heat from the PV cell, and simultaneously cool the PV cell for better overall performance. Hybrid concentrated photovoltaic-thermoelectric system (CPV-TE), is an innovative way to reuse the waste heat. This work focused on the circuit structure and current matching between the PV and TE module, and designed a two-terminal integrated CPV-TE device, comparing the electrical performances with a four-terminal device. Moreover, simulations of heat transfer and electronic performances of two CPV-TE devices have been conducted. The results show that the current of the TE module in the two-terminal device is 20 times higher than that of four-terminal one. Besides, the two-terminal device increases the difference in temperature between the hot end and the cold end of TE module. As a result, the power conversion efficiency (PCE) of the two-terminal CPV-TE device has been improved by 2.4%.","PeriodicalId":6816,"journal":{"name":"2021 18th China International Forum on Solid State Lighting & 2021 7th International Forum on Wide Bandgap Semiconductors (SSLChina: IFWS)","volume":"7 1","pages":"228-230"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90299800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}