太阳级硅材料少子寿命测试技术与仪器太阳级硅材料少子寿命测试技术与仪器匈牙利匈牙利SemilabSemilab公司上海代表处公司上海代表处 黄黄 黎黎2007.06Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com 少子寿命测试的基本原理和方法 表面钝化的方法介绍 少子寿命测试在光伏领域的应用 少子寿命测试仪的介绍目录：Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com少子寿命测试的基本原理和方法处于热平衡状态下的半导体，在一定温度下，载流子的浓度是一定的，称为平衡载流子浓度, 如果对半导体施加外界作用,破坏了热平衡的条件，称为非平衡状态。比平衡状态多出来的这部分载流子称为非平衡载流子。非平衡载流子分为非平衡多数载流子和非平衡少数载流子, 对于n型半导体材料，多出来的电子就是非平衡多数载流子,空穴则是非平衡少数载流子。对p型半导体材料则相反, 产生非平衡载流子的外界作用撤除以后，它们要逐渐衰减以致消失，最后载流子浓度恢复到平衡时的值, 非平衡少数载流子的平均生存时间称为非平衡少数载流子的寿命,简称少子寿命- 少子寿命的概念Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com测量方法都包括非平衡载流子的注入和检测两个基本方面。最常用的注入方法是光注入和电注入，而检测非平衡载流子的方法很多，如探测电导率的变化，探测微波反射或透射信号的变化等，这样组合就形成了许多寿命测试方法, 如: 直流光电导衰减; 高频光电导衰减; 表面光电压; 微波光电导衰减等 - 少子寿命测试的方法对于不同的测试方法，测试结果可能会有出入，因为不同的注入方法，厚度或表面状况的不同，探测和算法等也各不相同。因此，少子寿命测试没有绝对的精度概念，也没有国际认定的标准样片的标准，只有重复性，分辨率的概念。对于同一样品，不同测试方法之间需要作比对试验, 但比对结果并不理想Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com微波光电导衰减法(-PCD法)相对于其他方法，有如下特点：- 无接触、无损伤、快速测试- 能够测试较低寿命- 能够测试低电阻率的样品（最低可以测0.1ohmcm的样品）- 既可以测试硅锭、硅棒，也可以测试硅片或成品电池- 样品没有经过钝化处理就可以直接测试- 既可以测试P 型材料，也可以测试N 型材料- 对测试样品的厚度没有严格的要求- 该方法是最受市场接受的少子寿命测试方法- -PCD法Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com- -PCD法的测试原理Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com200 nsExcitation pulseV = V0 e-t/t tDetected w signaleff: 有效寿命, 也是测试寿命bulk : 体寿命sd: 表面复合影响的寿命S1, S2: 两个表面的复合速率d : 样品厚度D : 扩散系数 - -PCD法的测试模型Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com样品表面钝化方法介绍1、化学钝化碘酒法 - HF (5%)+ HNO3(95%) 去除表面损伤层 - 样品如放置较长时间，需HF 去除表面自然氧化层 - 样品用碘酒(0.2-5%)浸泡在塑料袋中测试2、电荷(Charge)钝化方法采用高压放电，在样品表面均匀 覆盖可控电荷，从而抑制表面复合m-PCD withchemical surface passivationCharge-PCDm-PCDaverage=14.6msaverage=953msaverage=1091ms3、热氧化法 样品表面生长高质量的氧化层钝化4、Semilab PTC 法 (Semilab Preface Treatment Chamber)Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com少子寿命测试在光伏领域的应用- 在单晶生长和切片生产中: 1. 调整单晶生长的工艺，如温度或速度 2. 控制回炉料，头尾料或其他回收料的比例 3. 单晶棒，单晶片的出厂指标检测- 在多晶浇铸生产中： 1. 硅锭工艺质量控制 2. 根据少子寿命分布准确判断去头尾位置- 电池生产中： 1. 进片检查 2. 工艺过程中的沾污控制 3. 每道工序后的检测： 磷扩散；氮化硅钝化；金属化等Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com- 单晶生长及单晶硅片Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com- 多晶浇铸及多晶硅片- 带硅和薄膜电池0.23m ms1.78m msCut offCut offBlockCuInGaSe FilmOn GlassRibbon SiliconAs cut waferSolar CellEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com- 量子效率和少子寿命的一致性Correlation between IQE and LifetimeCorrelation between IQE and LifetimeThe plot and the maps are originated from the IQE (internal quantum efficiency) resultsbased on LBIC and reflectance as well as frequency tuned m m-PCD measurements on a single crystalline sample performed by the WT-2000 system. Close correlation is shown in absolute numbers and also in lateral distribution of IQE and lifetime values. IQE vs. lifetime measured on the same waferIQE51.0%63.5%m m-PCD2.6m ms4.3m msl=980nmEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.comEffective lifetime has a direct influence on solar cell efficiency. If the effective lifetime is large enough than efficiency is larger for smaller surface recombination velocity (Sn).Efficiency=FF IscVoc / PlightFF: fill factor 0.75-0.85Isc: short circuit currentVoc: open circuit voltagePlight: luminous power- 少子寿命对转化效率的影响Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com15% 5” poly3.203us16.75% 5” mono3.431usAs cut wafer2.741usTextured wafer3.055usDiffused wafer9.738usNitrid Silicon Pass. 138.96us- 少子寿命在电池生产中应用举例Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.comThe use of bias light (continuous halogen lamp illumination) in solar cell measurementacts like natural sunlight and provides investigation of carrier lifetime under working conditions.In case of nitrid passivated silicon wafers bias light is necessary for compensatingtrapping effects. Measurement of bulk lifetime is only possible with bias light due to surfacedamages introduced during nitride film deposition.Lifetime measurement on nitrid coated samplesWithout bias lightt taverage=11.8m msWith bias lightt taverage=17.1m msOne point measurement withincreasing bias light intensity- 少子寿命测试中对陷阱缺陷(Trap Defects)效应的补偿Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.comWT-2000WT-1000多功能扫描系统，可选配：多功能扫描系统，可选配：u-PCD / carrier lifetime （少子寿命）（少子寿命）SPV / diffusion length （扩散长度）（扩散长度）LBIC / photovoltaic response （光诱导电流）（光诱导电流）bias light for all aboves （各种偏置光）（各种偏置光）reflectance / efficiency loss （反射率测试）（反射率测试）eddy current resistivity （电阻率测试）（电阻率测试）thickness and thickness variation （厚度测试）（厚度测试）Non-contact sheet resistance （方块电阻测试（方块电阻测试)少子寿命测试仪的介绍单点硅片单点硅棒或硅片Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com皮带传动，在线硅片自动检测（分选） 少子寿命 电阻率, 厚度(TTV), P/N型号 方块电阻在线硅锭检测- 在线检测设备Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com 谢谢！Thank You!Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.WWW.Semilab.com