简介:Chalcopyrite-typeCuInSe2nanoparticlesaresuccessfullypreparedbyusingIn2Se3nanoparticlesasaprecursorreactedwithcopperchloride(CuCl)solutionviaaphasetransformationprocessinlowtemperature.Thereactiontimeisakeyparameter.Afterthereactiontimeincreasingfrom0.5hto8h,In2Se3andCuClreactwitheachothergraduallyviaphasetransformationintoCuInSe2withoutanyintermediatephase.ThecrystallinestructureandmorphologyoftheCuInSe2nanoparticlesarecharacterizedbyX-raydiffraction(XRD)andfieldemissionscanningelectronmicroscopy(FESEM).ThediameterofCuInSe2nanoparticleswithgooddispersibilityrangesfrom10nmto20nm.ThebandgapoftheCuInSe2nanoparticlesis1.04eVcalculatedfromtheultraviolet-visible(UV-VIS)spectrum.
简介:Thispaperproposesanewtechniquethatisusedtoembeddepthmapsintocorresponding2-dimensional(2D)images.Sincea2Dimageanditsdepthmapareintegratedintoonetypeofimageformat,theycanbetreatedasiftheywereone2Dimage.Thereby,itcanreducetheamountofdatain3Dimagesbyhalfandsimplifytheprocessesforsendingthemthroughnetworksbecausethesynchronizationbetweenimagesfortheleftandrighteyesbecomesunnecessary.Weembeddepthmapsinthequantizeddiscretecosinetransform(DCT)dataof2Dimages.Thekeytothistechniqueiswhetherthedepthmapscouldbeembeddedinto2Dimageswithoutperceivablydeterioratingtheirquality.Wetrytoreducetheirdeteriorationbycompressingthedepthmapdatabyusingthedifferencesfromthenextpixeltotheleft.Weassumethatthereisonlyonenon-zeropixelatmostononehorizontallineintheDCTblockbecausethedepthmapvalueschangeabruptly.Weconductanexperimenttoevaluatethequalityofthe2Dimagesembeddedwithdepthmapsandfindthatsatisfactoryqualitycouldbeachieved.
简介:工作在中、长波红外波段(波长5-12μm)的红外探测器在红外制导、红外成像、环境监测及资源探测等方面有着重要而广阔的应用前景。目前中国军用和民用对这一波段的非制冷型、快速响应的光子型红外探测器有迫切需求。文中用熔体外延(ME)法在InAs(砷化铟)衬底上生长的InAs0.05Sb0.95(铟砷锑)厚膜单晶,制作了高灵敏度、非制冷型、中长波光导型探测器,探测器上安装了Ge(锗)浸没透镜。傅里叶变换红外(FTIR)吸收光谱显示InAsSb材料的本征吸收边出现在波长8μm以后。InAs0.05Sb0.95探测器的光谱响应波长范围为2-9μm。室温下,在波长6.5μm处的峰值探测率Dλp*达到5.4×10^9cm·Hz1/2·W^-1,在波长8.0μm和9.0μm处的探测率D*分别为9.3×10^8和1.3×10^8cm·Hz1/2·W^-1,显示了InAsSb探测器的优越性能及对红外探测和成像的应用前景。
简介:Wetheoreticallypresenttheintrinsiclimitstoelectronmobilityinthemodulation-dopedAlGaN/GaNtwo-dimensionalelectrongas(2DEG)duetoeffectsincludingacousticdeformationpotential(DP)scattering,piezoelectricscattering(PE),andpolar-opticphononscattering(POP).WefindthatDEandPEarethemoresignificantlimitingfactorsatintermediatetemperaturesof40Kto250K,whilePOPbecomesdominantasroomtemperatureisapproached.Detailednumericalresultsarepresentedforthechangeofelectronmobilitywithrespecttotemperatureandcarrierdensity.Weconcludethatthesethreetypesofphononscattering,whicharegenerallydeterminedbythematerialpropertiesbutnotthetechnicalprocessing,arehardlimitstothe2DEGmobility.
简介:研究表明含氟气体的性质决定了原子氟(F)的转化效率,通常在CxFy气体中x的值越大,氟(F)的转化效率也就会越高。所以C3F8(八氟丙烷)比C2F6(乙氟烷)具有更高的利用效率,更少的PFC(全氟化物)的排放。文章主要研究在以四乙氧基硅烷(TOES)为基础的离子增强化学气相沉积(PlasmaEnhancedChemicalVaporDeposition,PECVD)的清洗制程中,利用分解效率高的C3F8气体取代C2F6气体。通过实验设计(DesignOfExperiment,DOE),调整腔体压力、射频(RF)功率、气体流量等参数,最终得到最优化的新清洗配方。应用到实际的量产中,有效地降低了成本,减少了PFC的排放。
简介:提出了一种积累型槽栅超势垒二极管,该二极管采用N型积累型MOSFET,通过MOSFET的体效应作用降低二极管势垒。当外加很小的正向电压时,在N+区下方以及栅氧化层和N-区界面处形成电子积累的薄层,形成电子电流,进一步降低二极管正向压降;随着外加电压增大,P+区、N-外延区和N+衬底构成的PIN二极管开启,提供大电流。反向阻断时,MOSFET截止,PN结快速耗尽,利用反偏PN结来承担反向耐压。N型积累型MOSFET沟道长度由N+区和N外延区间的N-区长度决定。仿真结果表明,在相同外延层厚度和浓度下,该结构器件的开启电压约为0.23V,远低于普通PIN二极管的开启电压,较肖特基二极管的开启电压降低约30%,泄漏电流比肖特基二极管小近50倍。