共查询到20条相似文献,搜索用时 281 毫秒
1.
主要研究在晶体硅衬底上采用干氧氧化法生长SiO2薄膜,通过改变非晶SiO2薄膜的生长温度、时间以及气体流量等参数优化工艺条件,增强对硅片的钝化作用,提高光生少数载流子寿命.实验发现在840℃下生长的非晶SiO2薄膜对硅片钝化效果最佳,可将硅片少子寿命提高约90%.此外,为优化SiO2/SiNx双层膜的减反射作用,采用Matlab程序计算SiO2/SiNx双层膜的反射谱,从理论上获得最优的膜系组合.实验发现生长有SiO2钝化膜的SiO2/SiNx双层膜太阳电池相对单层SiNx膜太阳电池,短路电流和开路电压分别提高了0.2A和8mV,转换效率提高约9%. 相似文献
2.
3.
4.
5.
6.
7.
研究了优等化离子体化气相学沉积法(PECVD)在太阳能级n型直拉单晶(Cz)硅衬底上沉积i-a-Si:H薄膜工艺,得到较好的钝化效果。分析了气体流量和温度、气压等工艺参数对薄膜沉积和硅片钝化效果的影响。通过优化参数,钝化后在太阳能级n型Cz硅片(40×40mm)平均少子寿命值在800μs以上,局部在1500μs以上,得到了钝化后平均表面复合速率S<9.4cm/s的优良钝化效果;若硅片τbulk为2ms,则S<5.6cm/s。 相似文献
8.
9.
采用等离子体增强化学沉积的方法(PECVD),在低衬体温度下制备不同厚度的双面氮化硅薄膜,通过准稳态电导法(QSSPCD)测试non-diffused和diffused硅片沉积不同厚度双面氮化硅薄膜烧结前后的少子寿命,研究发现,氮化硅薄膜厚度在17 nm左右的时候,背面钝化效果有所下降,超过26 nm的时候,效果基本一致.non-diffused烧结后的少子寿命下降很大,而diffused与之相反.结果表明,采用氮化硅作为背面钝化介质膜,可以改善材料的少子寿命,背面钝化膜可以选择在26~75 nm之间. 相似文献
10.
以异质结(HIT)太阳电池的本征氢化非晶硅薄膜为研究对象,该HIT太阳电池采用n型硅片作为晶硅衬底,其n型电子传输层(下文简称为“n面”)为入光侧,p型空穴传输层(下文简称为“p面”)为背光侧。首先研究了n面和p面本征氢化非晶硅薄膜的厚度对膜层钝化性能和光透过率的影响,然后进一步研究了n面和p面本征氢化非晶硅薄膜不同厚度匹配设计对HIT太阳电池电性能的影响,并选出了最优厚度匹配方案。研究结果表明:1) n面本征氢化非晶硅薄膜的厚度越薄,n面非晶硅膜层的光透过率越高,但钝化效果会变差;当厚度达到5 nm时,硅片的少子寿命趋于稳定。2)在n面本征氢化非晶硅薄膜厚度一定的情况下,随着p面本征氢化非晶硅薄膜的厚度变厚,硅片的少子寿命先快速增加,当厚度达到9 nm时,硅片的少子寿命趋于稳定;当厚度大于9 nm时,制备的HIT太阳电池的短路电流和填充因子均下降,表明其串联电阻增大,导致光电转换效率降低。3)当n面和p面本征氢化非晶硅薄膜的厚度分别为5、9 nm时,n面的钝化效果和光透过率匹配较好,p面的钝化效果和电阻率匹配最优,即为最优厚度匹配方案;此方案制备得到的HIT太阳电池的光电转换效率达到... 相似文献
11.
We derive and apply a model that determines the effective minority carrier lifetime of macroporous crystalline silicon samples as a function of bulk lifetime, surface passivation and pore morphology. Two cases are considered: A layer of periodic macropores at the surface of a silicon wafer and a free standing macroporous silicon layer. We compare the model with experimental lifetime measurements for samples with randomly positioned macropores with a length of 10-40 μm. The pores have an average pore diameter of 2.4 μm and an average pore distance of 5.2 μm. The surface is passivated by thermal oxidation. The model agrees with the measurements if we assume an average surface recombination velocity S=24 cm/s at the pore surface. 相似文献
12.
Rabaa Bousbih Wissem Dimassi Ikbel Haddadi Sonia Ben Slema Paolo Rava Hatem Ezzaouia 《Solar Energy》2012,86(5):1300-1305
Hydrogenated films of silicon nitride SiNx:H are largely used as antireflective coating as well as passivation layer for industrial crystalline and multicrystalline silicon solar cells. In this work, we present a low cost plasma enhanced chemical vapor deposition (PECVD) of this thin layer by using SiH4 and N2 as a reactive gases. A study was carried out on the variation effect of the ratio silane (SiH4) to nitrogen (N2) and time deposition on chemical composition, morphologies, reflectivity and carrier lifetime. The thickness was varied, in order to obtain a homogeneous antireflective layer. The Fourier transmission infrared spectroscopy (FTIR) shows the existence of Si–N and Si–H bonds. The morphologies of the sample were studied by Atomic Force Microscopy (AFM). The resulting surface of the SiNx:H shows low-reflectivity less than 5% in wavelength range 400–1200 nm. As a result, an improvement in minority carrier lifetime has been achieved to about 15 μs. 相似文献
13.
由于等离子体增强化学的气相沉积(PECVD)法制备的SiOxNy薄膜中含有大量H原子,因而具有优异的表面钝化性能。通过在PERC太阳电池的Al2O3/SiNx背钝化叠层中间插入一层SiOxNy薄膜,形成Al2O3/SiOxNy/SiNx结构,可避免SiNx所带的固定正电荷对Al2O3负电荷场钝化效应的负面影响。试验结果表明,硅片少子寿命从原来的130 μs提高至162 μs,电池转换效率增加0.09%。同时,基于Al2O3/SiOxNy/SiNx背钝化的PERC太阳电池的LID也得到了改善,由对照组的1.83%下降到实验组的1.09%。 相似文献
14.
Bibhu P. Swain Hidetaka TakatoZhengxin Liu Isao Sakata 《Solar Energy Materials & Solar Cells》2011,95(1):84-88
Surface passivation has been recognized as a crucial step in the evaluation of minority carrier lifetime of photovoltaic materials as well as in the fabrication of high efficient solar cells. Dilute acids of HF and HCl are employed for germanium (Ge) surface passivation. An effective lifetime of passivated Ge wafers has been evaluated by a microwave photoconductive decay (μ-PCD) measurement. Surface recombination velocities, S, of H- and Cl-terminated Ge surfaces are 23 and 37 cm/s, respectively. The stability of passivated Ge surfaces against exposure to air has also been examined. The HCl-passivated Ge surfaces are found to be more robust than HF-passivated surfaces. 相似文献
15.
The effect of iron doping in electromagnetic cast (EMC) Si wafers on minority carrier recombination lifetime has been extensively investigated by means of microwave detected photo-conductivity decay (μ-PCD) and surface photo-voltage (SPV) to discriminate impurities and defects for the lower crystal quality. Optical and thermal activations of doped iron are investigated to study the difference between the two techniques in obtaining iron concentration. Minority carrier lifetimes increase or decrease after activation due to the different optical injection levels of both the SPV and μ-PCD techniques. No noticeable effect of chemical passivation in obtained iron concentration is observed. Boron and phosphorus gettering and hydrogen passivation techniques are applied to improve minority carrier recombination lifetime. As a result, the crystal quality of the EMC Si wafers depends on defect centers rather than on iron impurities. 相似文献
16.
The measurement of the bulk minority carrier lifetime of semiconductors requires efficient passivation of the recombination states at the surface. While numerous recipes have been published for Si-surface passivation, no adequate passivation methods are available for Ge. This paper presents a new and straightforward passivation method, based on a solution of iodine in polyvinyl acetate and acetone. The dependence of the carrier lifetime with time after passivation and with Ge resistivity has been investigated. It is found that the lifetime in this low resistivity material is strongly governed by Auger recombination. 相似文献
17.
18.
《Solar Energy》2013
An emitter wrap-through solar cell structure with diffused channels instead of drilled via-holes has been proposed in this study. The proposed solar cell, with p–n junctions near the surface and in the bulk, is expected to perform better due to (i) zero shadow loss, (ii) enhanced carrier collection from bulk and (iii) low surface coverage of metal. The device structure is simulated in Synopsys® Sentaurus simulator and is compared to the conventional solar cell structure devoid of surface texture. Variation of solar cell performance due to variations in minority carrier lifetime, channel doping, channel diameter and inter-channel spacing has been studied. It is observed that the bulk minority carrier lifetime and separation between channels affect the performance of the cell more than other parameters. Simulation results show that when electron lifetime in p-type is 10 μs and hole lifetime in n-type is 3 μs, the proposed solar cell (with small pitch values) gives 17.5% efficiency while conventional solar cell gives 16.1% efficiency. When minority carrier lifetime in p-type is 100 μs, the proposed solar cell (with small pitch values) gives 19.2% efficiency. 相似文献
19.
Surface passivation is one of the primary requirements for high efficient silicon solar cells. Though the current existed passivation techniques are effective, expensive equipments are required. In this paper, a comprehensive understanding of the SiO2 passivation layer grown by liquid phase deposition (LPD) was presented, which was cost-effective and very simple. It was found that the post-annealing process could significantly enhance the passivation effect of the LPD SiO2 film. Besides, it was revealed that both chemical passivation and field-effect passivation mechanisms played important roles in outstanding passivation effect of the LPD SiO2 film through analyzing the minority carrier lifetime and the surface recombination velocity of n-type and p-type silicon wafers. Although the deposition parameters had little influence on the passivation effect, they affected the deposition rate. Therefore, appropriate deposition parameters should be carefully chosen based on the compromise of the deposition rate and fabrication cost. By utilizing the LPD SiO2 film as surface passivation layer, a 19.5%-efficient silicon solar cell on a large-scale wafer (156 mm × 156 mm) was fabricated. 相似文献
20.
Young Do KimSungeun Park Jooyong SongSung Ju Tark Min Gu KangSoonwoo Kwon Sewang YoonDonghwan Kim 《Solar Energy Materials & Solar Cells》2011,95(1):73-76
The carrier lifetime of crystalline silicon wafers that were passivated with hydrogenated silicon nitride (SiNx:H) films using plasma enhanced chemical vapor deposition was investigated in order to study the effects of hydrogen plasma pre-treatment on passivation. The decrease in the native oxide, the dangling bonds and the contamination on the silicon wafer led to an increase in the minority carrier lifetime. The silicon wafer was treated using a wet process, and the SiNx:H film was deposited on the back surface. Hydrogen plasma was applied to the front surface of the wafer, and the SiNx:H film was deposited on the hydrogen plasma treated surface using an in-situ process. The SiNx:H film deposition was carried out at a low temperature (<350 °C) in a direct plasma reactor operated at 13.6 MHz. The surface recombination velocity measurement after the hydrogen plasma pre-treatment and the comparison with the ammonia plasma pre-treatment were made using Fourier transform infrared spectroscopy and secondary ion mass spectrometry measurements. The passivation qualities were measured using quasi-steady-state photoconductance. The hydrogen atom concentration increased at the SiNx:H/Si interface, and the minority carrier lifetime increased from 36.6 to 75.2 μs. The carbon concentration decreased at the SiNx:H/Si interfacial region after the hydrogen plasma pre-treatment. 相似文献