Analytical Model for Calculating Trapped Charge in a—Si：H and Its Relative Error Analysis

Using a Taylor series expansion for the Fermi-Dirac occupation func-tion,an accurate analytical model is developed for calculating the trapped-charge density in a-Si:H considering deep and tail states simultaneously without simplification.This is followed by the investigation of the relative errors of the localized trapped charge density in a-Si:H at all temperatures as a function of the quasi-Fermi levll in the band gap cal-culated from three published analytical models and our above model.The results suggest that the relative errors of all these models increase notably as Efn is very closed to Ec(e.g.,-0.01eV相似文献   

高分辨率a－Si：H摄象管制作工艺分析

高分辨率ａ－Ｓｉ：Ｈ摄象管制作工艺分析西北工业大学光电子研究室张哲ａ－Ｓｉ：Ｈ光导型摄象管靶面采用高阻ａ－Ｓｉ：Ｈ膜作光电导层，优点是无过荷开花，抗烧伤、高分辨，连续靶面，光谱响应覆盖可见区域且有红外延伸，靶面制作工艺简单，成本低，容易和微光管级联实...     

a－Si：O：H对硅平面三极管的表面钝化

采用ａ－Ｓｉ：Ｏ：Ｈ对硅平面三极管表面进行二次钝化，可以使器件正向特性曲线明显变平，饱和区、截止区变窄，反向击穿特性显著变硬，击穿电压有所提高，漏电流有了较大的减小，而且具有较强的Ｎａ￣＋阻挡能力。     

Size Control of Nanoscale Silicon Particles Formed in Thermally Annealed A-Si ： H Films and Its Photoluminescence

A method to control the size of nanoscale silicon grown in thermally annealed hydrogenated amorphous silicon （a-Si：H） films is reported. Using the characterizing techniques of micro-Raman scattering, X-ray diffraction and computer simulation, it is found that the sizes of the formed silicon particles change with the temperature rising rate in thermally annealing the a-Si ： H films. When the a-Si：H films have been annealed with high rising rate（～100℃/s）, the sizes of nanoscale silicon particles are in the range of 1.6～15nm. On the other hand, if the a-Si：H films have been annealed with low temperature rising rate（～1℃/s）, the sizes of nanoscale silicon particles are in the range of 23～46nm. Based on the theory of crystal nucleation and growth, the effect of temperature rising rate on the sizes of the formed silicon particles is discussed. Under high power laser irradiation, in situ nanocrystallization and subsequent nc-Si clusters are small enough for visible light emission, authors have not detected any visible photoluminescence（PL） from these nc-Si clusters before surface passivation. After electrochemical oxidization in hydrofluoric acid, however, intense red PL has been detected. Cyclic hydrofluoric oxidization and air exposure can cause subsequent blue shift in the red emission. The importance of surface passivation and quantum confinement in the visible emissions has been discussed.     

Prospects of aβ-SiC based IMPATT oscillator for application in THz communication and growth of a β-SiC p-n junction on a Ge modified Si 《100》 substrate to realize THz IMPATTs

The prospects ofa p<'+>nn<'+> cubic silicon carbide (3C-SiC/β-SiC)based IMPATT diode as a potential solidstate terahertz source is studied for the first time through a modified generalized simulation scheme.The simulation predicts that the device is capable of generating an RF power output of 63.0 W at 0.33 THz with an efficiency of 13%.The effects of parasitic series resistance on the device performance and exploitable RF power level are further simulated.The studies clearly establish the potential of 3C-SiC as a base semiconductor material for a high-power THz IMPATT device.Based on the simulation results,an attempt has been made to fabricate β-SiC based IMPATT devices in the THz region.Single crystalline,epitaxial 3C-SiC films are deposited on silicon (Si)(100)substrates by rapid thermal chemical vapour deposition (RTPCVD)at a temperature as low as 800℃ using a single precursor methylsilane,which contains Si and C atoms in the same molecule.No initial surface carbonization step is required in this method.A p-n junction with an n-type doping concentration of 4×10<'24> m<'-3> (which is similar to the simulated design data)has been grown successfully and the characterization of the grown 3C-SiC film is reported in this paper.It is found that the inclusion of Go improves the crystal quality and reduces the surface roughness.     

氢化非晶硅局域态电荷密度的解析统一模型

本文发展了一种简明的氢化非晶硅局域态电荷密度统一模型。从ａ－Ｓｉ材料的带隙态密度适配参数分布函数出发，采用Ｓｈｏｃｋｌｅｙ－Ｒｅａｄ－Ｈａｌｌ统计描述，推导出局域态电荷密度统一的解析表达式，该模型同时考虑了带尾局域态和缺陷局域态的作用。     

a-Si:C:H and a-Si:N:H Thin Films Obtained by PECVD for Applications in Silicon Solar Cells

Hydrogenated amorphous silicon-carbon (a-Si:C:H) and hydrogenated silicon-nitrogen (a-Si:N:H) antireflective films were deposited by plasma-enhanced chemical vapor deposition (PECVD) at 13.56 MHz in SiH₄ + CH₄ and SiH₄ + NH₃ gaseous mixtures of various compositions. The silicon and glass samples were investigated by optical spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). A correlation between film properties and process parameters was found. The refractive index decreased and the energy gap increased with an increase of carbon and nitrogen in the films. For some process parameters, it was possible to obtain smooth, hydrogen rich, and homogeneous films of low reflectivity. The silicon solar cells with antireflective coatings revealed an increase in efficiency.     

基于空间同步移相的1/4波片相位延迟量测量误差分析

本文对基于空间同步移相的1/4波片相位延迟量的测量误差进行了分析。检偏器阵列的方位角误差是引起波片相位延迟量测量误差的主要原因。分析结果表明波片相位延迟量的测量误差跟波片的快轴方位角有关。当待测1/4波片的快轴方位角为45°时,其相位延迟量测量结果基本不受检偏器阵列的方位角误差影响。因此,空间同步移相技术不仅可以实现1/4波片相位延迟量的快速测量,还可实现精确测量。     

异质结硅太阳能电池a—Si：H薄膜的研究

通过应用Scharfetter-Gummel数值求解Poisson方程，对热平衡态P^ （a-Si:H)/n(c-Si)异质结太阳能电池进行计算机数值模拟分析。结果指出，采用更薄P^ (a-Si：H）薄膜设计能有效增强光生载流子的传输与收集，从而提高a-Si/c-Si异质结太阳能电池的性能。同时，还讨论了P^ (a-Si:h)薄膜中P型掺杂浓度对光生载流了传输与收集的影响。高强茺光照射下模拟，计算表明，a-Si/c-Si异质结结构太阳能电池具有较高光稳定性。     

非晶硅中的硅氢键与光致亚稳缺陷

我们曾经提出:在a-Si∶H中光致亚稳缺陷的产生是由于Si-H键断裂,本文将进一步论述这种缺陷产生的可能微观机构,着重讨论微空洞在亚稳缺陷产生中的作用,并提出:光照不仅使悬键增多,同时也使Si-Si弱键增多的机构.     

a-Si:H TFT亚阈值区SPICE模型的研究

研究了将非晶硅薄膜晶体管（a-Si：H TFT）在电路模拟程序（SPICE）中使用的亚阈值区模型,将亚阈值区分为亚阈值前区和亚阈值后区并建立了模型,对比了不同模型下的模拟结果,发现亚阈值区的TFT特性依赖于材料性质,而且亚阈值前区和亚阈值后区的特性受栅源电压Vcs和漏源电压V DS的影响,呈指数变化。提出的新模型考虑了前界面态、后界面态、局域态、材料及制作工艺等因素,体现了该区域电流对漏源电压Vvs强烈的依赖关系。使用新模型对实验数据的拟合结果优于以往的模型,能够比较精确地模拟亚阈值区的特性,可用来预测a-Si：H TFT的性能．对TFT阵列的模拟设计具有重要价值。     

多端口反射计的任意相位单位矢量五点校准法及误差分析

本文讨论用五个任意相位的单位矢量来校准多端口反射计的方法。该方法使用简便,且适用于扫频测试。对于各类多端口反射计的校准、测量和误差分析,均是一种十分有效的方法。另外,本文利用该方法完成了对多端口反射计和误差分析,得到定量分析结果。     

A novel 3-TFT voltage driving method of compensating VTH shift for a-Si:H TFT and OLED degradation for AMOLED

This work demonstrates the feasibility of a novel pixel circuit by using three a-Si:H TFTs. The proposed circuit can stabilize the OLED current and provide an additional driving current to ameliorate the brightness degradation of the AMOLED. Measurement results indicate that the current degradation of the proposed circuit, caused by V_TH variations, is less than 5% over more than 50,000 s at 60 °C, whereas that of a conventional 2T1C pixel circuit is larger than 34%. Furthermore, to ameliorate the decrease in luminance owing to the OLED degradation, the OLED current can be increased by 10% by analyzing the current degradation and modulating the detected voltage appropriately.