StudyontheChargeTransferMechanismatStaticState inNTypeSiliconDopedGoldUsingStatisticMethod

应用统计方法，研究了掺金n型硅中各杂质能级上的电荷密度及载流子浓度随温度的变化，探讨了系统的静态电荷转移机制，所得结果支持了硅中金受主能级与施主能级本属同一金杂质的两个能级的认识。ItisstudiedthattheconcentrationofcarrierandthechargedensityonenergylevelsofimpuritiesintheNtypesilicondopedgoldvarywithtemperaturebystatisticmethod.Therebythechargetransfermechanismatstaticstateisapproached.Theresultssupporttheknowledgethatthegoldacceptorlevelandthegolddonorlevelinsiliconessentiallyoriginatefromthesamegoldimpurity

Application of Photovoltaic Method to Determination of the SurFace Recombination Velocity: N type GaAs

提出适用于可见光全波段的光伏测算gAAS单晶表面复合速度的新方法.实验结果表明，对于掺SI的n型弱简并gAAS单晶（n0＝2.0x1017CM-3），其表面复合速度SP＝1.6x105CM·S-1，与有关报道基本一致.Based on the surFace photovoltaic measurement, a new method applicable to Full wave band of the visible light at various temperatures is proposed For determination of the surFace recombination velocity of the N type GaAs single crystal.It is maniFested by the experiment that the surFace recombination velocity of the weak degenerated GaAs single crystal doped silicon ( n 0=2.0×10 17 cm -3 )is 1.6×10 5 cm·s -1 , which is essentially consistant with related reports.福建省自然科学基

Acquisition of Low Surface Recombination Velocityon Surface of p-type Si

提出减低 p- Si单晶表面复合速度参数值的两个行而有效的方法 ,解释了其不同的作用机理 .实验表明 ,经 HF腐蚀处理过的 p- Si单晶 ,自然晾干的表面复合速度测算值比红外灯烘干的测算值低 1个量级以上 ;而对于同一 p- Si单晶 ,置于氮气氛围之中的测算值要比大气之中的测算值低 2个量级以上The two effective measures for reducing value of the surface recombination veloc ity(SRV) on p Si sruface are proposed, and their different operational mechanis ms are also explained. It has been manifested by experiments that for p Si sing le crystal etched by solution HF∶H 2O=1∶1 and rinsed again with the deionized water, value of the SRV of this sample drie d then by airing lower than of this sample stoved then by infrared lamp for one order of magnitude and over, and value of the SRV of the sample in nitric gas environment more lower than of this sample in atmospheric environment for t wo orders of magnitude and over

Estimation for the Capture Cross Sections of Surface-State of Silicon Single Crystal by Photovoltaic Method

提出一个可以非破坏性地估算半导体单晶的表面态俘获截面σon和σ-p 的新方法 .此法基于变温光伏测量 ,采用 (111) p型硅单晶 (NA =1.5× 10 16cm-3 )为实验样品 .由于表面势垒高度ΦBP =0 .5 75 6 V,表面复合速度 sn =4 .8× 10 3 cm . s-1以及表面态密度 Ds=6 .7× 10 11cm -2 . e V-1可由光伏方法测算 ,则表面态俘获截面σon ≈ 5× 10 -13 cm2 与σ-p ≈ 2× 10 -12 cm2 可通过应用Shockley- Read体复合理论于表面而被估算 .此结果与其它方法得到的有关报导的结果相一致A new method which can nondestructively measure, then estimate the capture cross sections of surface state σ o n and σ - p (or σ n + and σ p 0) of silicon single crystal is proposed. This method is based on the photovoltage measurements at various temperatures. The photovoltage experiment was carried out with a (111) p Si single crystal ( N A =1.5×10 16 cm -3 ). Owing to that the surface barrier height Φ BP =0.575 6 V, the surface recombination velocity S n =4.8×10 3 cm·s -1 and the surface state density D s =6.7×10 11 cm -2 ·eV -1 of the sample can be determined by photovoltaic method, the capture cross sections of surface state σ o n ≈5×10 -13 cm 2 and σ - p ≈2×10 -12 cm 2 can also be estimate by applying Shockley Read bulk recombination theory for surface. This result is consistent with related results obtained by other method

Analysis of EFFect of SnO_2 Film Form on Its Gas Sensitivity by X-Ray DiFFraction

通过X光衍射图分析，确认了较低温度下CVd法生长的非掺杂SnO2晶膜含有较多的偏离SnO2配位的晶体成份，从而定性地解释了该晶膜具有较高的气体敏感度的现象。Through analysing X-ray diFFraction patterns, it is conFirmed that more crystal compositions deviating From SnO2 coordination are contained in undoped SnO2 Film CVD-grown at lower temperature.So it is explained that this Film has higher gas sensitivity.国家与福建省自然科学基

Study on Vacuum Sensitive Mechanism of Surface States Silicon by Photovoltaic Method

根据光伏方法研究的半导体表面气体分子吸附机理 ,提出了硅单晶表面态真空敏感效应的机理模型 ,解释了表面态敏感型的真空传感器的各有关观测结果 .因此可以确认 ,硅单晶表面态对真空敏感的实质原因就是由于构成大气主要成份的氮气和氧气两种元素的电子亲和势相对于硅元素 ,具有明显不同的且符号相反的差值 ,导致吸附于硅表面的 N2 、O2 分子与硅表面态之间不同转移方向的电荷转移差值可以随真空度变化所引起的A mechanism model of the sensitive effect of vacuum conditions on the surface states of silicon crystal is proposed,from study on the adsorption mechanism of gaseous molecules on the surface of semiconductor by photovoltaic method.Consequently the relative observed results from the vacuum sensors based on the surface state sensitivity are clearly explained.Thereby,it can be confirmed that the essential cause of the vacuum sensitive for the surface states of silicon is that the electron affinity potentials of nitrogen element and oxygen element,relative to of silicon element,have obviously different and sign opposite difference values.It can cause the charge transfers with different directions between N 2,O 2 molecules adsorbed on silicon surface and the surface states of silicon and their difference value varies with the change of vacuousness

STUDY ON THE ADSORPTION MECHANISM OF GASEOUS MOLECULES ON SURFACE OF SEMICONDUCTOR BY PHOTOVOLTAIC METHOD

通过对 p型和n型的同一硅单晶样品分别置于大气、氧气、氮气的不同氛围中所进行的各有关表面参量的光伏测算 ,分析了同一样品处于不同氛围中 ,以及不同导电类型的样品处于同一氛围中的测算结果的变化规律 ,探讨了出现这一规律的内在机理 ,解释了各有关的物理现象 .The relative surface parameters were determined by photovoltaic method in p and n type silicon in a wafer under the atmospheric, oxygenic, and nitric environments, respectively. The inherent mechanism is approached according to the parameter variations, and the relative physical phenomena are explained

Study of the Characteristic and Parameters of Semiconductor Material

提出超晶格 (Al As/ Ga As)和应变超晶格 (Gex Si1-x/ Si,Inx Ga1-x As/ Ga As)光伏效应的机理 ,测量了不同温度下的光伏谱 ,光伏曲线反映了台阶二维状态密度分布并观察到跃迁峰 .计算了导带和价带子带的位置和带宽 ,根据宇称守恒确定光跃迁选择定则 ,对跃迁峰进行指认 .研究了光伏随温度变化、激子谱峰半高宽随温度和阱宽的变化 ,讨论谱峰展宽机制中的声子关联 ,混晶组分起伏及界面不平整对线宽的影响 .测量了元素和化合物半导体单晶材料的室温、低温下的表面光电压谱 ,推导了有关计算公式 ,计算得出电学参数 (L、n0 、μ、S、W)、深能级和表面能级位置、带隙和化合物组分 ;分析了电学参数的温度关系 ;由双能级复合理论 ,研究了少子扩散长度与深能级关系 ,计算了深能级浓度和参数 .在不同条件下研制了二氧化锡 /多孔硅 /硅 (Sn O2 / PS/ Si)和二氧化锡 /硅 (Sn O2 / Si) ,测量了它们的光伏谱 ,分析表明它们存在着异质结 .当样品吸附还原性气体 (H2 、CO、液化石油气 )时 ,光电压有明显变化 ,因此可做为一种新的敏感元件 .分析了它们的吸附机理 ,计算了有关参数The mechanism of the photovoltaic effect for superlattices(AlAs/GaAs) and strained superlattices(Ge xSi 1-x /Si,In xGa 1-x As/GaAs)are discussed. The photovoltage spectra at different temperatures have been measured. The curves of SPV reflect the step like distribution of two dimensional state density, and transition peaks have been observed. The levels and bandwidths of the subbands have been calculated. The transition speaks are assingned according to the selection rule for optical transition based on the conservation law of parit. The changed in photovoltage with temperature, the full width of half maxium of the transition peaks as a function of temperature and well width for different samples are investigated. The influences of exciton phonon coupling, alloy disorder and interface roughness on the broading mechanism of the transition peaks are discussed. The surface photovoltage of element and compounds single crystal semiconductors are measured at room and low temperatures. Some calculation formules are derived. The electrical parameters (L,n 0,μ,S,W),deep levels and surface level, energy gap and composition of the compounds are determined. The temperature dependence of the electrical parameters are analyzed. The dependence of minority carrier diffusion length on deep level are studied by double level recombination theory. The concentration and parameters of deep levels are calculated. Tin Oxide/Porous Silicon/Silicon(SnO 2/PS/Si)and Tin Oxide/Silicon are fabricated at different conditions. The photovoltage spectra of SnO 2/PS/Si and SnO 2/Si have been studied. It is shown that there exist heterojunctions in SnO 2/PS/Si and SnO 2/Si. The photovoltage changes evidently when the sample absorbes reducing gas (H 2,CO,liguified petroleum). The experimental results indicate that SnO 2/PS/Si or SnO 2/Si is a good material for gas sensor. The mechamism for the gas absorption of SnO 2/PS/Si and SnO 2/Si are discussed. The parameters are calculated.国家自然科学基金资助项目!(技准 36 1号 ;6 86 6 0 52 ;;59172 10 1) ;; 教育部科研资助项目 ;; 福建省自然科学基金资助项目!(F950