Study of the Intrinsic Recombination Velocity at the Junction of Silicon Solar under Frequency Modulation and Irradiation

In this study, a method for determining the intrinsic recombination velocity at the junction of a silicon solar cell is presented. The expression of intrinsic recombination velocity at the junction was established under irradiation in frequency modulation. Based on this expression, an electrical model of the intrinsic recombination velocity at the junction is presented.

Bifacial Silicon Solar Cell Steady Photoconductivity under Constant Magnetic Field and Junction Recombination Velocity Effects

The paper reported a theoretical study on the photoconductivity of a bifacial silicon solar cell under polychromatic illumination and a constant magnetic field effect. By use of the continuity equation in the base of the solar cell maintained in a constant temperature at 300 K, an expression of the excess minority carriers’ density was determined according to the applied magnetic field, the base depth and the junction recombination velocity. From the expression of the minority carriers’ density, the photoconductivity of the solar cell was deduced and which allowed us to predict some recombination phenomena, the use of such solar cell in optoelectronics. The profile of the photoconductivity also permitted us to utilize a linear model in order to determine an electrical capacitance that varied with magnetic field.

Back Surface Recombination Velocity Modeling in White Biased Silicon Solar Cell under Steady State

In this paper, we extend the concept of back surface recombination through a study of a silicon mono facial solar cell in static regime and under polychromatic illumination. Back surface recombination velocities noted Sbe, Sbj and Sbr are determined for which respectively we derived, the power, the fill factor and the conversion efficiency, that become constant whatever the thickness of the solar cell. We have then obtained the expression of the minority carrier’s density in the base from the continuity equation. We then have determined the photocurrent density, the photo voltage, the power, the fill factor and finally the conversion efficiency.

Ac Recombination Velocity in a Lamella Silicon Solar Cell

The silicon solar cell with series-connected vertical junction is studied with different lamella widths—the expression of the ac recombination velocity of the excess minority carrier at the back surface is established. Spectroscopy technique reveals dominated impact of the lamella widths of the base.

AC Recombination Velocity in the Back Surface of a Lamella Silicon Solar Cell under Temperature

The ac recombination velocity of the excess minority carriers, in the back surface of a silicon solar cell with a vertical junction connected in series, is developed through Einstein’s law giving the diffusion coefficient of minority carriers according to temperature, through mobility. The frequency spectrum of both, amplitude and phase, are produced for the diffusion coefficient and the recombination velocity in the rear face, in order to identify the parameters of equivalent electric models.

Profile Measurement of Ion Temperature and Toroidal Rotation Velocity with Charge Exchange Recombination Spectroscopy Diagnostics in the HL-2A Tokamak

This paper deals with the profile measurement of impurity ion temperature and toroidal rotation velocity that can be achieved by using the charge exchange recombination spectrum （CXRS） diagnostics tool built on the HL-2A toknmak. By using CXRS, an accurate impurity ion temperature and toroidal plasma rotation velocity profile can be achieved under the condition of neutrM beam injection （NBI） heating. Considering the edge effect of the line of CVI 529.06 nm （n= 8-7）, which contains three lines （active exciting spectral line （ACX）, passivity exciting spectral line （PCX） and electron exciting spectral line （ICE））, and using three Gaussian fitted curves, we obtain the following experimental results： the core ion temperature of HL-2A device is nearly thousands of eV, and the plasma rotation velocity reaches about 104 m· s^-1. At the end of paper, some explanations are presented for the relationship between the curves and the inner physical mechanism.

A.C. Recombination Velocity as Applied to Determine n⁺/p/p⁺Silicon Solar Cell Base Optimum Thickness

This work deals with determining the optimum thickness of the base of an n+/p/p+ silicon solar cell under monochromatic illumination in frequency modulation. The continuity equation for the density of minority carriers generated in the base, by a monochromatic wavelength illumination (λ), with boundary conditions that impose recombination velocities (Sf) and (Sb) respectively at the junction and back surface, is resolved. The ac photocurrent is deduced and studied according to the recombination velocity at the junction, to extract the mathematical expressions of recombination velocity (Sb). By the graphic technique of comparing the two expressions obtained, depending on the thickness (H) of the base, for each frequency, the optimum thickness (Hopt) is obtained. It is then modeled according to the frequency, at the long wavelengths of the incident light. Thus, Hopt decreases due to the low relaxation time of minority carriers, when the frequency of modulation of incident light increases.

AC Back Surface Recombination Velocity in n⁺-p-p⁺Silicon Solar Cell under Monochromatic Light and Temperature

Excess minority carrier’s diffusion equation in the base of monofaciale silicon solar cell under frequency modulation of monochromatic illumination is resolved. Using conditions at the base limits involving recombination velocities Sf and Sb, respectively at the junction (n+/p) and back surface (p+/p), the AC expression of the excess minority carriers’ density δ (T, ω) is determined. The AC density of photocurrent Jph (T, ω) is represented versus recombination velocity at the junction for different values of the temperature. The expression of the AC back surface recombination velocity Sb of minority carriers is deduced depending on the frequency of modulation, temperature, the electronic parameters (D (ω)) and the thickness of the base. Bode and Nyquist diagrams are used to analyze it.

The Efficiency of a p-n Solar Diode as a Function of the Recombination Velocity within the Depletion Layer

The role of the carrier’s recombination velocity Si within the depletion Layer of p-n junction solar cell and the external bias voltage Va across the junction in determining the current density “J” through the cell is revealed. The unsteady carrier diffusion equation is solved under illumination conditions considering a source spectral function G(λ). The efficiency of the device as a function of Si , Va , G(λ) is obtained. Computations considering a silicon solar cell are given as an illustrative example.

AC Back Surface Recombination Velocity as Applied to Optimize the Base Thickness under Temperature of an (n+-p-p+) Bifacial Silicon Solar Cell, Back Illuminated by a Light with Long Wavelength

The bifacial silicon solar cell, placed at temperature (T) and illuminated from the back side by monochromatic light in frequency modulation (ω), is studied from the frequency dynamic diffusion equation, relative to the density of excess minority carriers in the base. The expressions of the dynamic recombination velocities of the minority carriers on the rear side of the base Sb1(D(ω, T);H) and Sb2(α, D(ω, T);H), are analyzed as a function of the dynamic diffusion coefficient (D(ω, T)), the absorption coefficient (α(λ)) and the thickness of the base (H). Thus their graphic representation makes it possible to go up, to the base optimum thickness (Hopt(ω, T)), for different temperature values and frequency ranges of modulation of monochromatic light, of strong penetration. The base optimum thickness (Hopt(ω, T)) decreases with temperature, regardless of the frequency range and allows the realization of the solar cell with few material (Si).

Two-Dimensional Finite Element Method Analysis Effect of the Recombination Velocity at the Grain Boundaries on the Characteristics of a Polycrystalline Silicon Solar Cell

To take into account the variation of the recombination velocity at the grain boundaries, we present in this paper a new approach of characterization of the solar cells, based on the two dimensional finite element method. The results of this study on a bifacial polycrystalline silicon solar cell, modelled in the rectangular form, highlighting the effects of the boundary recombination velocity (Sgb) on the solar cell electrical parameters. The photogenerated excess carrier’s density, the photocurrent density;the phototovoltage and the current-voltage characteristics are analyzed, namely. A good agreement with the results given in the literature is observed.

Surface Recombination Concept as Applied to Determinate Silicon Solar Cell Base Optimum Thickness with Doping Level Effect

New expressions of back surface recombination of excess minority carriers in the base of silicon solar are expressed dependent on both, the thickness and the diffusion coefficient which is in relationship with the doping rate. The optimum thickness thus obtained from the base of the solar cell allows the saving of the amount of material needed in its manufacture without reducing its efficiency.

Junction Surface Recombination Concept as Applied to Silicon Solar Cell Maximum Power Point Determination Using Matlab/Simulink: Effect of Temperature

In this work, we study the method for determining the maximum of the minority carrier recombination velocity at the junction Sfmax, corresponding to the maximum power delivered by the photovoltaic generator. For this, we study the temperature influence on the behavior of the front white biased solar cell in steady state. By solving the continuity equation of excess minority carrier in the base, we have established the expressions of the photocurrent density, the recombination velocity on the back side of the base Sb, and the photovoltage. The photocurrent density and the photovoltage are plotted as a function of Sf, called, minority carrier recombination velocity at the junction surface, for different temperature values. The illuminated I-V characteristic curves of the solar cell are then derived. To better characterize the solar cell, we study the electrical power delivered by the base of the solar cell to the external charge circuit as either junction surface recombination velocity or photovoltage dependent. From the output power versus junction surface recombination velocity Sf, we have deduced an eigenvalue equation depending on junction recombination velocity. This equation allows to obtain the maximum junction recombination velocity Sfmax corresponding to the maximum power delivered by the photovoltaic generator, throughout simulink model. Finally, we deduce the conversion efficiency of the solar cell.

Growth-Promoting Effect of Recombinant Human Growth Hormone and Stanozolol in Girls with Turner Syndrome

Summary: Ten girls with Turner syndrome were treated with a combination therapy of recombinant human growth hormone (R hGH) and low dose stanozolol for a period of 8 to 36 months. The results showed that when compared with the growth rate before the treatment, the growth rates after treatment with R hGH and stanozolol showed a sustained increase, reaching 9.0±1.9 cm/year during the first year of treatment; the height age increase by 2.5±0.8 years while the bone age increase were 1.0±0.7 years; and the predicted final adult height at the end of the first year of the treatment increased to 149.4±6.1 cm compared to their original mean of 142.8±4.2 cm. We are led to conclude that therapy with R hGH in combination with stanozolol can increase the growth velocity and significantly increase the predicted adult height of children with Turner syndrome.

生长激素治疗特纳氏综合征临床观察

目的探讨基因重组人生长激素（recombinant human growth hormone,rhGH）对特纳氏综合征（turner syndrome,TS）患儿促身高增长的疗效。方法TS患儿60例,每晚睡前接受rhGH治疗0.15～0.18IU/（kg·d）,疗程3～34个月,并对其疗效进行观察。结果治疗3,6,12个月和24个月后,平均生长速率（2.33±0.71）cm/年分别增至（8.51±1.31）,（8.37±0.88）,（7.56±1.35）,（7.18±1.89）cm/年,治疗后体重和骨龄无明显变化。治疗期间除少数肝功能轻度异常,注射部位轻度反应外,未发现明显不良反应。结论大剂量rhGH对TS患儿有增快生长速度和改善最终身高作用。

不同剂量基因重组人生长激素治疗特发性矮小症效果及对糖脂代谢、甲状腺功能影响

目的探讨不同剂量基因重组人生长激素治疗特发性矮小症效果及对糖脂代谢、甲状腺功能影响。方法选取2017年7月-2018年7月收治的特发性矮小症患儿86例,根据基因重组人生长激素使用剂量不同将其分为A组和B组,每组43例。A组每日睡前皮下注射基因重组人生长激素0.15 U/kg,B组每日睡前皮下注射基因重组人生长激素0.20 U/kg,疗程均为1年。比较两组治疗后1年临床效果,治疗前和治疗后1年糖代谢、脂代谢、甲状腺功能指标,以及治疗期间不良反应发生情况。结果治疗后1年,两组身高、生长速度、骨龄和预测成年身高较治疗前增加或增快,空腹胰岛素、三酰甘油和低密度脂蛋白胆固醇较治疗前下降,且A组身高、生长速度、骨龄和预测成年身高低于或慢于B组,差异有统计学意义(P<0.05);两组组间糖代谢、脂代谢和甲状腺功能指标比较差异无统计学意义(P>0.05)。治疗期间,两组空腹血糖>6.5 mmol/L、注射部位红肿、生长痛和头痛发生率比较差异均无统计学意义(P>0.05)。结论基因重组人生长激素治疗特发性矮小症患儿效果确切,其中每日给予0.20 U/kg效果优于每日给予0.15 U/kg,且未造成糖代谢、脂代谢、甲状腺功能明显变化,未增加不良反应。

用微波光电导谱研究半导体薄片的少子扩散长度和表面复合速度

当半导体薄片同时受到微波和光照射时,通过样品的微波传输系数与光的波长有关,当光的波长连续地变化时,微波传输系数也连续地变化。本文分析了在半导体薄片中的少子扩散长度、少子寿命及表面复合速度与上述微波传输系数的变化△T之间的关系,并通过测量半导体薄片的微波光电导谱计算这些参数。研究表明,可以从微波光电导谱中的△T的峰值位置直接算出少子扩散长度。这是一种无接触、无损伤的快速测试方法,测试区域是直径为3mm的一个圆斑,样品可以在测试台上自由移动。本方法的测试结果与其它方法所得的结果是较为一致的。

模拟分析少子复合速率及吸收层对HIT太阳电池性能的影响

采用AMPS-1D程序模拟分析了前后接触少子复合速率以及吸收层的厚度和少子迁移率对非晶硅/单晶硅异质结太阳电池光伏性能的影响.模拟发现,与太阳电池的前接触少子复合速率相比,背接触少子复合速率对太阳电池光伏性能的影响更为显著.吸收层单晶硅的厚度对太阳电池光伏性能的影响要受到单晶硅隙间缺陷态密度以及背接触少子复合速率的制约.当背接触复合占主要地位时,吸收层越厚电池的转换效率越高;当吸收层隙间缺陷复合占主要地位时,电池的转换效率在某一厚度处达到峰值.吸收层的少子迁移率对太阳电池性能的影响,也要受到背接触少子复合速率的制约.当背接触复合速率较低时,少子迁移率越大,电池的转换效率越高;当背接触复合速率较高时,少子迁移率越小,电池的转换效率越高.

不同表面复合速率情况下IBC太阳电池发射区半宽度研究

利用TCAD半导体器件仿真软件对N型插指背接触（Interdigitated Back Contact,IBC）单晶硅太阳电池发射区半宽度进行研究,全面系统地分析了在不同背表面复合速率的情况下,发射区半宽度对IBC太阳电池短路电流密度（JSC）、开路电压（VOC）、填充因子（FF）及转换效率（Eff）的影响。结果表明：随着背表面复合速率的增大,对于不同发射区半宽度的情况,IBC太阳电池JSC、VOC、FF及Eff均显著降低。当背表面复合速率一定时,发射区半宽度越大,JSC、VOC越高,而FF越低。随着发射区半宽度的增大,IBC太阳电池Eff呈现先增大后减小的变化特点。当背表面复合速率较小（50~500 cm/s）时,最优的发射区半宽度为800μm。当背表面复合速率较高（≥5000 cm/s）时,最优的发射区半宽度为1200μm。

CdTe钝化的HgCdTe非平衡载流子表面复合速度的实验研究

利用Ar+束溅射沉积技术在HgCdTe表面实现了低温CdTe介质薄膜的低温生长.在同一HgCdTe晶片表面分别用CdTe介质膜、HgCdTe自身阳极氧化膜进行表面钝化.利用光电导衰退测量技术测量了两种不同表面钝化的薄HgCdTe晶片的非平衡载流子(少数载流子)寿命,并通过光电导衰减信号波形的拟合,得到两种不同表面钝化的HgCdTe表面复合速度.实验结果表明。