CdS/CdTe太阳电池的背接触

磷硝酸腐蚀是一种适宜于工业化生产的背表面刻蚀工艺.文中采用磷硝酸腐蚀CdTe薄膜,并用溴甲醇腐蚀作为对照实验,研究了两种腐蚀对材料性质的影响.随后用真空蒸发法分别沉积了四种背接触层,提出了适宜于工业化生产的背接触技术,并从实验和理论上对两种背接触结构的CdTe太阳电池进行了分析.     

碲化锌插入层对碲化镉太阳电池性能参数影响的分析

分析了有ZnTe/ZnTe∶Cu插入层的CdTe太阳电池在能带结构上的变化.通过对比有无插入层的CdTe太阳电池在C-V特性、I-V特性、光谱响应上的不同,肯定了插入层对改善背接触特性的作用,发现它还可以改善器件前结CdS/CdTe的二极管特性和短波光谱响应.实验结果还表明,不掺杂的ZnTe对提高器件的效率是必要的.恰当的不掺杂层厚度和退火温度能有效地改进CdTe太阳电池的性能,而对填充因子的提高最为显著.     

n型IBC太阳电池磷掺杂工艺

为了兼顾叉指背接触(IBC)太阳电池背表面场(BSF)区域的钝化性能和接触性能,在现有IBC太阳电池制备工艺基础上引入离子注入技术,对电池背表面场区域进行磷离子注入.研究了不同磷离子注入剂量对IBC电池钝化性能和接触性能的影响,并研究了烧结工艺对IBC电池接触性能的影响.实验结果表明,当磷离子注入剂量为6.6×1014...     

温度循环下CdS/CdTe太阳电池稳定性的研究

对CdS/CdTe太阳电池在温度循环下的稳定性进行了研究,测定了其I-V特性曲线,并与室温下的电池作了比较.结果表明:经温度循环后电池的转换效率、填充因子和短路电流密度都有不同程度的下降,而用ZnTe作背接触层的电池稳定性有所改善.     

氩氧气氛下沉积的CdTe薄膜及太阳电池的性质

研究了在氩氧气氛下近空间升华沉积CdTe的技术.发展了在表面十分平整的玻璃衬底上沉积优质CdTe薄膜的方法,对比了在玻璃衬底和CdS薄膜上CdTe薄膜的结构特征.通过研究氧分压对CdTe薄膜择优取向的影响,证实了在恰当的近空间升华沉积过程中,两种衬底上的CdTe薄膜具有相同的结构.研究了玻璃衬底上CdTe薄膜的电学与光学性质,观察了后处理对上述薄膜性质的影响,并研制出了效率达13.38%的小面积CdTe薄膜太阳电池.     

利用碳糊成膜法改进CdTe太阳电池背处理工艺

提出一种新型的制备Cd％太阳电池背接触方法。利用碳糊成膜法,将含Cu、Te的CdCl2浆状悬浊液涂覆在CdTe表面,只进行一次后退火,X射线衍射（XRD）、二次质子谱（SIMS）测试发现,就能同时达到CdCl2后处理的作用、形成CuxTe的缓冲层和降低背接触势垒的目的。实验结果表明。本文方法将传统的CdCl2后处理和形...     

近空间升华沉积CdTe薄膜的微结构和PL谱

用近空间升华法在CdS薄膜上沉积了CdTe薄膜.研究了在两种保护气氛下所沉积的多晶CdTe薄膜在后处理后的微结构、表面形貌及光致发光(PL)谱,并研究了CdTe表面和CdS/CdTe界面的PL谱的区别,根据薄膜的微结构对碲化镉在太阳电池中的应用进行了讨论.     

近空间升华沉积CdTe薄膜的微结构和PL谱

用近空间升华法在CdS薄膜上沉积了CdTe薄膜.研究了在两种保护气氛下所沉积的多晶CdTe薄膜在后处理后的微结构、表面形貌及光致发光(PL)谱,并研究了CdTe表面和CdS/CdTe界面的PL谱的区别,根据薄膜的微结构对碲化镉在太阳电池中的应用进行了讨论.     

分子束外延HgCdTe薄膜的CdTe缓冲层特性研究

CdTe是GaAs衬底上分子束外延(MBE)HgCdTe薄膜时的缓冲层,引入缓冲层的目的是减小失配位错,CdTe缓冲层的生长直接影响到后续HgCdTe薄膜的制备质量,然而目前现有文献鲜有报道CdTe缓冲层的最佳厚度.采用X射线双晶衍射、位错腐蚀坑密度(EPD)、FT-IR和椭圆偏振光谱的方法,从CdTe缓冲层厚度对位错密度的影响入手,分析并确定了理想的CdTe缓冲层厚度.     

束源杂质引发的MBE HgCdTe表面缺陷

研究了利用GaAs作为衬底的HgCdTe MBE薄膜的表面缺陷,发现其中一类缺陷与Hg源中杂质有关.采用SEM对这类缺陷进行正面和横截面的观察,并采用EDX对其正面和横截面进行成分分析.并设计了两个实验:其一,在CdTe/GaAs衬底上,低温下用Hg源照射20min,再在其上继续高温生长CdTe;其二,在CdTe/GaAs衬底上,一直用Hg源照射下高温生长CdTe.两个实验后CdTe表面都出现与HgCdTe表面相比在形状和分布上类似的表面缺陷,采用光学显微镜和SEM对CdTe表面缺陷进行了观察,通过CdTe表面缺陷和HgCdTe表面缺陷的比较,我们证实了这类表面缺陷的成核起源于Hg源中杂质.     

Stable CdTe thin film solar cells with a MoOx back‐contact buffer layer

MoO_x thin films were employed as a buffer layer in the back contact of CdTe solar cells. A monograined CdS layer was employed as the window layer to reduce light absorption. The insertion of a MoO_x buffer layer in the back contact greatly reduced the Schottky barrier leading to increased fill factor and open‐circuit voltage. A CdTe solar cell, with an efficiency as high as 14.2%, was fabricated. The use of a MoO_x buffer layer made it possible to fabricate high‐efficient CdTe solar cell with much less Cu in the back contact, thus greatly enhancing the cell stability. Copyright © 2015 John Wiley & Sons, Ltd.     

Focussed ion beam and field emission gun–scanning electron microscopy for the investigation of voiding and interface phenomena in thin‐film solar cells

The use of focussed ion beam milling combined with high resolution scanning electron microscopy analysis as a characterisation tool for thin‐film photovoltaics is reported. CdTe solar cell cross sections are examined in high detail with as‐grown and CdCl₂‐treated devices being compared. Observed changes in microstructure of the thin‐film layers are related to the device performance. The CdCl₂ treatment is shown to cause a reduction in the CdTe defect density at regions close to the interface and induce recrystallization of the CdS layer. Furthermore, the focussed ion beam technique is shown to reveal voids formed within the device's thin‐film layers at various processing stages that have not been previously observed in working cell structures. The back‐contacting Te‐rich layer resulting from nitric–phosphoric acid etching is also observed, with the etched layer being seen to propagate down the CdTe grain boundaries. Copyright © 2011 John Wiley & Sons, Ltd.     

氩氧气氛下沉积的CdTe薄膜及太阳电池的性质

研究了在氩氧气氛下近空间升华沉积CdTe的技术．发展了在表面十分平整的玻璃衬底上沉积优质CdTe薄膜的方法,对比了在玻璃衬底和CdS薄膜上CdTe薄膜的结构特征．通过研究氧分压对CdTe薄膜择优取向的影响,证实了在恰当的近空间升华沉积过程中,两种衬底上的CdTe薄膜具有相同的结构．研究了玻璃衬底上CdTe薄膜的电学与光学性质,观察了后处理对上述薄膜性质的影响,并研制出了效率达1338%的小面积CdTe 薄膜太阳电池．     

Structural and optical properties of CdTe-nanocrystals thin films grown by chemical synthesis

By mans of a chemical synthesis technique stoichiometric CdTe-nanocrystals thin films were prepared on glass substrates at 70 °C. First, Cd(OH)₂ films were deposited on glass substrates, then these films were immersed in a growing solution prepared by dissolution of Te in hydroxymethane sulfinic acid to obtain CdTe. The structural analysis indicates that CdTe thin films have a zinc-blende structure. The average nanocrystal size was 19.4 nm and the thickness of the films 170 nm. The Raman characterization shows the presence of the longitudinal optical mode and their second order mode, which indicates a good crystalline quality. The optical transmittance was less than 5% in the visible region (400–700 nm). The compositional characterization indicates that CdTe films grew with Te excess.     

Evaporated Te on CdTe: A vacuum-compatible approach to making back contact to CdTe solar cell devices

A commonly used process for forming low-resistance contacts to thin-film p-type CdTe involves the formation of a Te layer by etching the CdTe film in a concentrated mixture of nitric and phosphoric acids. The authors compare evaporated Te back contacts with ‘control’ back contacts formed by the usual etching process, and demonstrate that evaporating Te onto a CdTe thin film is a viable process for forming a low-resistance contact. The best efficiency achieved for a CdTe solar cell made with an evaporated Te back contact is 12.1%, whereas the efficiency of the device made with the control back contact was 11.9%. The evaporation process offers numerous advantages over acid etching, most notably vacuum compatibility amenable to large-scale production of CdTe solar cell modules.     

Investigation of oxide layer on CdTe film surface and its effect on the device performance

In this work, the chemical evolution of CdTe crystal and thin film under air exposure was investigated by X-ray Photoelectron Spectroscopy (XPS). In particular, the analysis of Te 3d core level allowed us to characterize the surface oxidation. Indeed, in both cases and after a short air exposure, the Te 3d peaks exhibited clearly two components corresponding to Te–Cd and Te–O, i.e. bulk CdTe and native oxide. The later one was used to estimate an equivalent oxide layer thickness. Only a weak oxide amount could be observed on both fresh surfaces, whereas after two days of air exposure, the native oxide thickness was estimated to 2.2 nm and 0.9 nm for CdTe crystal and thin film respectively. For a longer exposition time of one month, the oxide layer thickness increased in both cases up to 7.2 and 5.9 nm, for CdTe crystal and thin film respectively. Even, if the oxidation kinetic appeared slower in the case of CdTe thin film, such insulating oxide layer formation at CdTe surface under air exposure might have negative effect on the ohmic back contact formation and further electrical characteristics of solar cells. Next to this study, aged CdTe samples were submitted to a chemical etching after several days of air exposure and before solar cell fabrication. It appeared that solar cell based on ‘aged CdTe layer’ after etching exhibit electrical performances similar to those obtained with a freshly elaborated CdTe device. Therefore, CdTe chemical etching appears as an effective way to remove the surface oxide layer and retrieve good cell performances. As a result, it is possible to store CdTe films for long duration before solar cells fabrication.     

CuxS背接触层制备及在碲化镉薄膜太阳电池中应用研究

本文采用化学水浴法沉积CuxS薄膜,通过改变Cu元素比例研究其对碲化镉电池效率的影响。研究表明化学水浴法沉积的CuxS是非晶的,采用适当退火条件可以使其晶化,随着退火温度的提高,薄膜变得致密且结晶明显。CuxS薄膜厚度对电池性能有很大的影响,结果表明,随着CuxS薄膜厚度增加,电池性能先增加后减少。薄膜厚度为75nm时,CdS/CdTe电池性能最佳,达到了最高转化效率(η)为12.19%,填充因子(FF)为68.82%,开路电压(Voc)为820mV。     

Role of Morphology of Surfactant-Free Nanoparticles in Organic Photovoltaics

Journal of Electronic Materials - Nanoparticulate (NP) films and organic photovoltaic devices have been fabricated from poly(3-hexylthiophene):phenyl C61 butyric acid methyl ester (P3HT:PC61BM) NP...     

太阳电池中CdS薄膜的制备及其性能的研究

分别采用化学池沉积(CBD)和真空蒸发法,在三种衬底(玻片、ITO玻片、SnO2玻片)上沉积CdS薄膜,并利用扫描电镜(SEM)、透射光谱、X射线衍射(XRD)等方法对沉积膜进行了测试分析,同时阐述了两种不同方法下CdS膜的生长沉积机制。