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1.
The close-to-optimal band gap, large absorption coefficient, low manufacturing cost and rapid increase in power conversion efficiency make the organic-inorganic hybrid halide (CH3NH3PbI3) and related perovskite solar cells very promising for commercialization. The properties of point defects in the absorber layer semiconductors have important influence on the photovoltaic performance of solar cells, so the investigation on the defect properties in the perovskite semiconductors is necessary for the optimization of their photovoltaic performance. In this work, we give a brief review to the first-principles calculation studies on the defect properties in a series of perovskite semiconductors, including the organic-inorganic hybrid perovskites and inorganic halide perovskites. Experimental identification of these point defects and characterization of their properties are called for.  相似文献   

2.
Laser doping offers a promising method to define selective emitters for solar cells. Its main advantage is the localised nature of the laser beam, which allows melting of the surface area without heating the bulk. The ability to perform this process over a dielectric film offers further benefits, such as the possibility of creating self‐aligned metallisation patterns simultaneously with the selective emitter formation. However, laser induced defects, contaminations and discontinuities in the selective emitter can reduce solar cell performance. In this work the influence of different dielectric films on defect formation is investigated. It was found that a thin oxide beneath the SiNx improves the implied open circuit voltage of the solar cells for a wide range of laser output powers. Fewer defects were observed when using this SiO2/SiNx stack compared to the standard single SiNx anti‐reflection coating layer. It was also found that the recrystallised silicon layer grows epitaxially according the substrate orientation. No dislocation or stacking faults were observed in deeper areas using transmission electron microscopy, although some defects were observed near the surface. Electron beam induced current images revealed discontinuities in junctions formed with high laser powers. We conclude that micro‐cracks create these discontinuities, which can potentially induce shunts. Finally, laser doped solar cells with a standard SiNx and with a double SiO2/SiNx stack layer as anti‐reflection coating were compared. An efficiency of 18.4% on a large area commercial grade p‐type CZ substrate was achieved. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

3.
Single crystal substrates (0.2 Ω cm, boron doped) purposely doped at 2 × 1014 cm−3 with titanium were used to assess the effect of titanium on solar cell performance. Comparisons were made of all-epitaxial, diffused junction epitaxial, and all diffused junction solar cells fabricated on these substrates. In all cases lower than normal short-circuit current densities were obtained due to diminished red response. However, the short-circuit currents and efficiencies for the epitaxial cells were higher than those for the cells made by direct diffusion into the bulk titanium-doped silicon. The highest efficiency obtained for an epitaxial cell on a titanium-doped substrate was 11.7%. The research reported herein was supported by Jet Propulsion Laboratory, California Institute of Technology under contract No. 954817 and RCA Laboratories, David Sarnoff Research Center, Princeton, New Jersey.  相似文献   

4.
The effect of dissociation of interstitial iron‐substitutional boron (FeiBs) pairs, as it occurs under illumination in iron‐contaminated silicon solar cells, on the solar cell properties has been studied on the basis of numerical device simulations using reported recombination parameters for Fei and FeiBs. Most cell parameters are found to degrade during FeiBs dissociation. However, the open‐circuit voltage can also increase within certain ranges of the iron concentration. Critical iron concentrations are determined, giving the threshold contamination level above which a significant degradation in the corresponding cell parameter can be observed. The threshold iron contamination level of the open‐circuit voltage degradation is found to be up to two orders of magnitude larger than the threshold iron level of the short‐circuit current degradation. As the behaviour of the cell parameters under illumination is specific to the dissociation of FeiBs pairs, the characteristic changes in the cell parameters due to illumination may be used as a simple way of identifying iron contamination problems in silicon solar cells. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

5.
Adnan Shariah  Feda Mahasneh 《半导体学报》2022,43(12):122701-1-122701-7
Silicon solar cells continue to dominate the market, due to the abundance of silicon and their acceptable efficiency. The heterojunction with intrinsic thin layer (HIT) structure is now the dominant technology. Increasing the efficiency of these cells could expand the development choices for HIT solar cells. We presented a detailed investigation of the emitter a-Si:H(n) layer of a p-type bifacial HIT solar cell in terms of characteristic parameters which include layer doping concentration, thickness, band gap width, electron affinity, hole mobility, and so on. Solar cell composition: (ZnO/nc-Si:H(n)/a-Si:H(i)/c-Si(p)/a-Si:H(i)/nc-Si:H(p)/ZnO). The results reveal optimal values for the investigated parameters, for which the highest computed efficiency is 26.45% when lighted from the top only and 21.21% when illuminated from the back only.  相似文献   

6.
Thin films of SiN are well suited as antireflection (AR) coatings for Si solar cells because their optical properties, such as refractive index and absorption coefficient, can be tailored during deposition to match those of Si solar cells. The SiN layers, particularly those deposited by a plasma-enhanced chemical vapor deposition (PECVD) process, can serve other functions in Si solar-cell fabrication. They can be excellent buffer layers through which the front metal contact can be fired. The PECVD nitridation also introduces H into the Si surface, which diffuses deep into the solar cell and passivates residual impurities and defects during metal-contact firing. The optimization of SiN properties and processing conditions may have conflicting demands based on its multifunctional role. To fully exploit these multiple functions, the SiN processing sequence must be optimized based on the properties of the nitride, the diffusion behavior of H, and the interactions of metal with the SiN/Si composite substrate.  相似文献   

7.
The precipitation rate of intentionally introduced iron during low-temperature heating is studied among a variety of single-crystal and polycrystalline silicon solar cell materials. A correlation exists between the iron precipitation rate and the carrier recombination rate in dislocation-free as-grown material, suggesting that diffusion-length-limiting defects in as-grown material are structural defects which accelerate iron precipitation. Phosphorous diffusion gettering was found to be particularly ineffective at improving diffusion length after intentional iron contamination in materials with high iron precipitation rates. We propose that intragranular structural defects in solar cell silicon greatly enhance transition metal precipitation during cooling from the melt and become highly recombination-active when decorated with these impurities. The defects then greatly impair diffusion length improvement during phosphorus gettering and limit carrier lifetimes in as-grown material.  相似文献   

8.
Optical and electrical simulations were carried out for thin film silicon solar tandem cells with intermediate reflector layer (IRL) between top and bottom cell and compared with experimental external quantum efficiency and current voltage characteristics results. Reference data were collected from a series of tandem cells with different thicknesses of the top cell absorber layer (160–240 nm), the bottom cell absorber layer (1750–2100 nm), and the transparent conductive oxides based IRL (10–80 nm). It turned out that for capturing correctly the influence of the IRL on the light management as a function of the IRL thickness, the conventional semicoherent approach is not sufficient. Whereas the optical properties of a very thin IRL are governed by interference effects that are best calculated using a fully coherent model, increasingly thicker IRL show a more and more incoherent behavior. By taking into account, the interface morphology and angular light distribution within the cell stack an algorithm for the effective IRL reflectivity was proposed that explains the experimental findings very well. The consecutive electrical simulations were carried out with the device simulator ASA. The dependence of short circuit current density jsc and fill factor FF on the thickness dIRL of the IRL is in qualitative agreement between simulation and experiment showing coincident extrema in jsc(dIRL) and FF(dIRL) at the current matching point. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

9.
In this study, we investigate the metallization‒induced recombination losses of high efficiency bifacial n‒type and p‒type crystalline Si solar cells. From the experimental data, we found that the most efficiency limiting parameter by the screen‒printed metallization is the open‒circuit voltage (VOC) of the cells. We investigated the mechanism responsible for this loss by varying the metallization fraction on either side of the cell and determined the local enhancement in the dark saturation current density beneath the metal contacts (J0(met)). Under optimum fabrication conditions, the J0(met) at metal‒p+ (boron) emitter interfaces was found to be significantly higher compared with the values obtained for metal‒n+ emitters. A two‒dimensional simulation model was used to get further insight into the recombination mechanism leading to these VOC losses. The model assumes that metal contacts penetrate (or etch) into the diffused region following the firing process and depassivate the interface. Applying this model to our n‒type solar cells with a boron p+ emitter, we demonstrated that the simple loss of passivated area beneath the metal contact cannot explain the degradation observed in the VOC of the cell without considering a significant etching or metal penetration into the emitter region. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

10.
鲁伟明  王志刚  胡辉 《半导体学报》2015,36(9):092002-6
晶体硅组件的电势诱导衰减是现在的晶体硅电池组件在高电压系统下广泛面临的失效模式。常规组件的测试方法需要至少96小时的测试时间。在本文中,我们试图通过实验找到一种快速的太阳能电池的抗电势诱导衰减性能的方法。采用NaCl溶液作为Na+源, PVB 作为封装材料,我们能够在1小时内完成实验。在使用了新的抗电势诱导衰减工艺的太阳能电池上也成功进行了测试。经过试验证明实验前后电池片的反向电流的变化是很重要的判断标准。通常具有抗电势诱导衰退性能的电池反向漏电试验后变化是小于2倍的。电池的结果和相对应的组件的测试结果进行了比较,结果显示两者吻合的很好。  相似文献   

11.
Photovoltaic devices with nanostructured active layers have attracted considerable attention for their outstanding light‐trapping capability. Although with the promise of an efficient light‐conversion, the realistic performance is still far from expectation. This is because the detailed electrical mechanisms have seldom been included into the design, leading to a substantial discrepancy between prediction and reality. This paper reports a complete optoelectronic simulation for nanowire and nanohole solar cells by addressing electromagnetic and carrier‐transport response in a coupled finite‐element method. The effects of surface/bulk recombination are quantified and compared for nanowire and nanohole solar cells with radial and axial doping profiles. Our results reveal that the axially doped silicon cells are extremely sensitive to surface recombination because of the large surface‐to‐volume ratio and lateral recombination loss, eventually reducing the photocurrent and light‐conversion efficiency. Relatively, radially doped silicon cells with a moderate nanowire length show some improvement relative to axially doped cells, but nevertheless remain very sensitive to recombination losses. Comparison of the light‐trapping and electrical performance between nanowire and nanohole solar cells is also given. The methodology is applicable for nanostructured solar cells based on various semiconductor materials and system configurations, and is expected to play a promising role in accurately predicting the performance of the new‐generation light‐conversion devices. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

12.
郭占苗 《电子设计工程》2012,20(13):131-134
为了满足客户对太阳能电池组件性能的更高要求,通过对电池片的EL测试,从来料方面进行把关,通过对层压敷设件和组件的EL测试,能够合理的控制由于工艺参数设置不当和人为因素引起的组件不良缺陷,从而能够将问题消灭在组件出厂之前,保证组件质量。同时,通过分析EL图像,也有助于完善和改进电池片以及组件的生产工艺,对太阳能电池的生产有重要指导意义。  相似文献   

13.
综述了近年来各种硅微纳结构的特征和制备技术,介绍了其在新型太阳电池中的应用现状与前景.首先,阐述了硅微纳结构在传统p-n结、新型径向p-n结以及异质结太阳电池结构设计中的研究进展;其次,从光吸收增强、表面修饰及钝化的角度,分析了硅微纳结构太阳电池的增效措施;最后,提出了柔性硅微纳结构太阳电池开发的新思路.  相似文献   

14.
Silver nanoparticles embedded in a dielectric material have strong scattering properties under light illumination, due to localized surface plasmons. This effect is a potential way to achieve light trapping in thin‐film solar cells. In this paper we study light scattering properties of nanoparticles on glass and ZnO, and on silver coated with ZnO, which represent the back reflector of a solar cell. We find that large nanoparticles embedded in the dielectric at the back contact of amorphous silicon solar cells lead to a remarkable increase in short circuit current of 20% compared to co‐deposited cells without nanoparticles. This increase is strongly correlated with the enhanced cell absorption in the long wavelengths and is attributed to localized surface plasmons. We also discuss the electrical properties of the cells. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

15.
Deep level traps are observed in silicon that has been implanted with high doses of arsenic and subsequently annealed by rapid thermal annealing. The doses studied create enough damage to form a surface amorphous layer. Annealing temperatures, implant fluence, and the presence of a surface amorphous layer contribute to the type of trap observed. These results show evidence for a clustering/declustering mechanism of arsenic in silicon during rapid thermal annealing.  相似文献   

16.
All-small-molecule organic solar cells (ASM-OSCs), which consist of small-molecule donors and acceptors, have recently been studied extensively to eliminate the batch-to-batch variation from polymer-based donor or acceptor. On the other hand, the control of their active layer morphology is more challenging due to the similar chemical structure and miscibility of small-molecule donor and small-molecule accepter. Hence, this study develops a dual-additive-driven morphology optimization method for ASM-OSCs based on BTR-Cl:Y6. One solid additive – 1,4-diiodobenzene (DIB) and one liquid additive – diiodomethane (DIM) are selected, making use of their distinct interaction mechanisms with Y6 and BTR-Cl. It is found that DIB can form a eutectic phase with Y6, which can increase the intermolecular interactions and modulate the acceptor phase separation, while the simultaneous volatilization of DIM suppresses the over-aggregation of BTR-Cl during the film casting process. As a result of the synergistic morphology tuning, the optimized device delivers a power conversion efficiency (PCE) as high as 15.2%, among the highest PCE reported to date for binary ASM-OSCs without solvent annealing treatment. This work demonstrates the potential of morphology tuning via the incorporation of dual additives into ASM-OSCs, enabling them to achieve comparable efficiencies to those of conventional polymer/small-molecule based OSCs.  相似文献   

17.
利用金属辅助硅化学刻蚀法在晶体硅表面制备 了 大面积有序硅纳米结构,并基于金属辅助硅化学刻蚀的机理,实现了硅纳米结构从线阵列到 孔阵列转变。漫反射光谱的测试结果表 明,相对于平面、金字塔结构,硅纳米孔织构的晶体硅具有卓越的减反光性能,在300100nm 光谱范围内的AM1.5G太阳光子的光反射损失比低于3.6%。硅纳米孔阵列减反光性能优异, 制备方法简单、快速,且其孔壁互连,有益于晶体硅太阳电池的后续制备工艺及其表面结构 机械稳定,可作为减反光结构应用于晶体硅太阳电池。  相似文献   

18.
The high-power microwave (HPM) effect heats solar cells, which is an important component of a satellite. This creates a serious reliability problem and affects the normal operation of a satellite. In this paper, the different HPM response characteristics of two kinds of solar cells are comparatively researched by simulation. The results show that there are similarities and differences in hot spot distribution and damage mechanisms between both kinds of solar cell, which are related to the amplitude of HPM. In addition, the duty cycle of repetition frequency contributes more to the temperature accumulation of the solar cells than the carrier frequency. These results will help future research of damage assessment technology, reliability enhancement and the selection of materials for solar cells.  相似文献   

19.
We have extended a previous model for calculating the effects of dislocations on the characteristics of a Si solar cell to include the effects of front and back surface recombination. This improved dislocation model uses Green's function approach to solve the three‐dimensional continuity equation of the minority carriers with suitable boundary conditions corresponding to surface recombination at the n and p sides. The dislocations are considered to be localized lines, extending perpendicular to the front and back surfaces of the cell and having a recombination velocity. We discuss effect of several parameters such as bulk dislocation density, minority carrier diffusion length in p and n regions on the J‐V characteristics, and spectral response of the cell. It is shown that these results agree well with previously published, experimental data. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

20.
A novel type silicon nanocrystal-based hybrid solar cell is demonstrated here, where two individual junctions are designed carefully and arranged in parallel with each other. It is found that complementary absorption can be realized by double parallel junctions, and more photons in a wide energy range can be absorbed. As a result, device efficiency has been enhanced more than twice compared to single junction reference device. In addition, its working principles are also studied extensively.  相似文献   

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