简介:RamanscatteringspectroscopyisappliedtoinvestigatethephononmodesinGaxIn1-xP(x=0.52)and(AlxGa1-x)0.51In0.49P(x=0.29)alloys.Two-modebehaviorinGaxIn1-xPandthree-modebehaviorin(AlxGa1-x)0.51In0.49Pareobserved.InorderedGaxIn1-xP,weclearlydistinguishtheTO1(GaP-like)modeandthesplittingofLO1(GaP-like)andLO2(InP-like)modes,whichisbelievedtobetheresultofsuperlatticeeffectofordering,andtheLO1+LO2mode,whichisobservedforthefirsttime.Inadditiontotheb/aratio,it'sfoundthattherelativeintensityoftheFLAandtheLO1+LO2modesalsocorrespondstothedegreeoforder.TheTO1andthesplittingofLO1andLO2devotetogethertothereductionofthe'valleydepth'.In(AlxGa1-x)0.51In0.49P,thedoublingofFLAisobserved.DuetotheinfluenceofAlcomposition,theGaP-likeLOmodebecomesashoulderoftheInP-likeLOmode.TheunresolvedRamanspectraindicatetheexistenceoforderedstructurein(AlxGa1-x)0.51In0.49Palloys.
简介:MOTOROLAP2K系列手机出现“无信号”故障,大部分是由于U900(电源IC)无法输出V—BOOST(5.6V)电压造成,只要将U900换新即可解决,但有些机型的U900是封胶的,取下很容易造成主板断线而报废,而且U900往往只是无法输出V—BOOST(5.6V)电压,其它功能均正常,弃之可惜,为此有人就加上一个能产生5V电压的电路(如以前768改768C用的升压电路),确实能很好地解决该问题,可就是该升压电路有些难找。笔者经多次实验,找到了一种更简洁的方法,只要增加一个二极管、一个电容(电容可在原机上拆得)和一根漆包线即可解决问题。
简介:针对抗辐照SOIPMOS器件的直流特性与低频噪声特性展开试验与理论研究,分析离子注入工艺对PMOS器件电学性能的影响,并预测其稳定性的变化。首先,对离子注入前后PMOS器件的阈值电压、迁移率和亚阈摆幅进行提取。测量结果表明:埋氧化层离子注入后,器件背栅阈值电压由-43.39V变为-39.2V,空穴有效迁移率由127.37cm2/Vs降低为80.45cm2/Vs,亚阈摆幅由1.35V/dec增长为1.69V/dec;结合背栅阈值电压与亚阈摆幅的变化,提取得到埋氧化层内电子陷阱与背栅界面态数量的变化。随后,分析器件沟道电流噪声功率谱密度随频率、沟道电流的变化,提取γ因子与平带电压噪声功率谱密度,由此计算得到背栅界面附近的缺陷态密度。基于电荷隧穿机制,提取离子注入前后埋氧化层内陷阱态随空间分布的变化。最后,基于迁移率随机涨落机制,提取得到离子注入前后PMOS器件的平均霍格因子由6.19×10-5增长为2.07×10-2,这表明离子注入后器件背栅界面本征电性能与应力稳定性将变差。
简介:Theinfluenceofp-typeGaN(pGaN)thicknessonthelightoutputpower(LOP)andinternalquantumefficiency(IQE)oflightemittingdiode(LED)wasstudiedbyexperimentsandsimulations.TheLOPofGaN-basedLEDincreasesasthethicknessofpGaNlayerdecreasesfrom300nmto100nm,andthendecreasesasthethicknessdecreasesto50nm.TheLOPofLEDwith100-nm-thickpGaNincreasesby30.9%comparedwiththatoftheconventionalLEDwith300-nm-thickpGaN.ThevariationtrendofIQEissimilartothatofLOPasthedecreaseofGaNthickness.ThesimulationresultsdemonstratethatthehigherlightefficiencyofLEDwith100-nm-thickpGaNisascribedtotheimprovementsofthecarrierconcentrationsandrecombinationrates.
简介:Poly4-vinylphenol(P4VP)/multi-wallcarbonnanotubes(MWNTs)multi-layersensitivefilmsweredepositedoninterdigitatedelectrodesbyairbrushtechnologytodetecttoluenevaporatroomtemperature.Thesurfaceandsectionmorphologiesofthemulti-layerfilmswereobservedbyascanningelectronmicroscope(SEM).Itisfoundthattheresistanceofthesensorincreaseswhenitisexposedtotoluenevaporandtheresponsehasagoodlinearitywiththeconcentrationoftoluene.TheresultsshowthattheP4VP/MWNTsthree-layerfilmsensorshavebettersensingpropertiescomparedwiththetwo-layerfilmsensors.Therelatedsensingmechanismisstudiedindetail.