AFM Studies on the Morphological Evolution of Chemically Deposited In2S3 Thin Films as a Function of Deposition Time

2006 ◽  
Vol 945 ◽  
Author(s):  
Merida Sotelo-Lerma ◽  
Omar Armando Castelo-Gonzalez ◽  
Rafael Ramirez-Bon ◽  
Francisco Javier Espinoza-Beltran

ABSTRACTIndium sulphide (In2S3) is a very promising semiconductor material for window layers in solar cell devices. It is currently being investigated for high efficiency solar cell based on Cu(In,Ga)Se2-In2S3 heterostructures. The chemical bath deposition (CBD) technique is one of the most convenient methods to obtain In2S3 films because of its simplicity, low cost and some other advantages. Amorphous and polycrystalline In2S3 films on glass substrates have been obtained by the CBD technique. Like in many others CBD processes, the deposition mechanism and kinetic growth of In2S3 films on glass substrates is not very well understood [1-6]. In this work we have chemically deposited In2S3 films for different times from 6 up to 39 hours, in order to study by atomic force microscopy (AFM) the formation of the films on glass substrates. The AFM measurements were performed in a liquid medium in which the cantilever tip and the sample are completely immersed in the liquid. A specially designed AFM cell is composed of a tip attached to a circular transparent window, the liquid level is between the upper and lower surface of the window, and a circular meniscus is established around the window, preventing the tip could be affected or destroyed by the surface tension of the liquid. By using this liquid AFM technique, we can at real-time observe the thin film forming process, and thereby clearly reveal the growing mechanism. It is an ideal and more practical tool for in situ investigation of samples which are normally found in liquid environments.

1992 ◽  
Vol 258 ◽  
Author(s):  
M. Yoshimi ◽  
W. Ma ◽  
T. Horiuchi ◽  
C. C. Lim ◽  
S. C. De ◽  
...  

ABSTRACTA series of experimental investigations has been made on the a-Si // poly-Si tandem solar cell which is one of the most promised candidate of high cost-performance photovoltaic cell, e.g., high efficiency, low cost with almost no light induced degradation. Employing high conductivity with wide optical band gap p type microcrystalline SiC (μ-SiC) as a window material together with a-SiC as an interface buffer layer and also n type μc-Si as a back ohmic contact layer in the poly-Si based bottom cell, the conversion efficiency of 17.2 % has been obtained. Combining an optically transparent a-Si p-i-n cell as a top cell with an optical coupler between the top and the poly-Si bottom cell, a total efficiency of 20.3 % has been obtained so far on the four-terminal stacked mode structure. A systematic technical data for the optimization of cell structure variation on the developed tandem solar cells are presented and further possibility to improving the performance are discussed.


2014 ◽  
Vol 1 (3-4) ◽  
Author(s):  
Nikhil Jain ◽  
Mantu K. Hudait

AbstractAchieving high-efficiency solar cells and at the same time driving down the cell cost has been among the key objectives for photovoltaic researchers to attain a lower levelized cost of energy (LCOE). While the performance of silicon (Si) based solar cells have almost saturated at an efficiency of ~25%, III–V compound semiconductor based solar cells have steadily shown performance improvement at ~1% (absolute) increase per year, with a recent record efficiency of 44.7%. Integration of such high-efficiency III–V multijunction solar cells on significantly cheaper and large area Si substrate has recently attracted immense interest to address the future LCOE roadmaps by unifying the high-efficiency merits of III–V materials with low-cost and abundance of Si. This review article will discuss the current progress in the development of III–V multijunction solar cell integration onto Si substrate. The current state-of-the-art for III–V-on-Si solar cells along with their theoretical performance projections is presented. Next, the key design criteria and the technical challenges associated with the integration of III–V multijunction solar cells on Si are reviewed. Different technological routes for integrating III–V solar cells on Si substrate through heteroepitaxial integration and via mechanical stacking approach are presented. The key merits and technical challenges for all of the till-date available technologies are summarized. Finally, the prospects, opportunities and future outlook toward further advancing the performance of III–V-on-Si multijunction solar cells are discussed. With the plummeting price of Si solar cells accompanied with the tremendous headroom available for improving the III–V solar cell efficiencies, the future prospects for successful integration of III–V solar cell technology onto Si substrate look very promising to unlock an era of next generation of high-efficiency and low-cost photovoltaics.


2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Tsung-Wei Chang ◽  
Chao-Te Liu ◽  
Wen-Hsi Lee ◽  
Yu-Jen Hsiao

In this study, commercially available white paint is used as a pigmented dielectric reflector (PDR) in the fabrication of a low-cost back electrode stack with an Al-doped ZnO (AZO) layer for thin-film silicon solar cell applications. An initial AZO film was deposited by the radio-frequency magnetron sputtering method. In order to obtain the highest transmittance and lowest resistivity of AZO film, process parameters such as sputtering power and substrate temperature were investigated. The optimal 100-nm-thick AZO film with low resistivity and high transmittance in the visible region are 6.4 × 10−3 Ω·cm and above 80%, respectively. Using glue-like white paint doped withTiO2 nanoparticles as the PDR enhances the external quantum efficiency (EQE) of a microcrystalline silicon absorptive layer owing to the doped white particles improving Fabry–Pérot interference (FPI), which raises reflectance and scattering ability. To realize the cost down requirement, decreasing the noble metal film thickness such as a 30-nm-thick silver reflector film, and a small doping particle diameter (D50 = 135 nm) and a high solid content (20%) lead to FPI improvement and a great EQE, which is attributed to improved scattering and reflectivity because of optimum diameter (Dopt) and thicker PDR film. The results indicate that white paint can be used as a reflector coating in low-cost back-electrode structures in high-performance electronics.


2019 ◽  
Vol 37 (1) ◽  
pp. 127-135 ◽  
Author(s):  
W. Christopher Immanuel ◽  
S. Paul Mary Deborrah ◽  
S.S.R. Inbanathan ◽  
D. Nithyaa Sree

AbstractPolycrystalline chalcogenide semiconductors play a vital role in solar cell applications due to their outstanding electrical and optical properties. Among the chalcogenide semi-conductors, CdZnS is one kind of such important material for applications in various modern solid state devices such as solar cells, light emitting diode, detector etc. Due to their applications in numerous electro-optic devices, group II-VI semiconductors have been studied extensively. In recent years, major attention has been given to the study of electrical and optical properties of CdZnS thin films. In this work, Cd1−xZnxS thin films were prepared by chemical bath deposition technique. Phase purity and surface morphology properties were analyzed using field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD) studies. Chemical composition was studied using energy dispersive spectrophotometry (EDS). Optical band gap property was investigated using UV-Spectroscopy. Electrical conductivity studies were performed by two probe method and thermoelectric power setup (TEP) to determine the type of the material. This work reports the effect of Zn on structural, electrical, microstructural and optical properties of these films.


2012 ◽  
Vol 534 ◽  
pp. 197-200
Author(s):  
Bo Zhang

InSnTaO films were deposited on glass substrates by magnetron sputtering with ITO target and tantalum target. X-ray diffractometer (XRD) and atomic force microscopy (AFM) revealed that InSnTaO films had better crystalline structure, larger grain size and lower surface roughness than ITO films. Ta-doping remarkably improved the optical-electrical characteristics. The films showed obvious Burstin-Moss effect with substrate temperature. Moreover, the direct transition model showed wider optical band gap of InSnTaO films than that of ITO films. As a result, InSnTaO films prepared by co-sputtering revealed better comprehensive properties than traditional ITO films.


Author(s):  
Tieyu Gao ◽  
Yue Bing Zheng ◽  
Bala Krishna Juluri ◽  
Tony Jun Huang

We have fabricate ordered Au nanodisk and nanohole arrays on glass substrates using nanosphere lithography (NSL) combined with reactive ion etching (RIE) techniques. The morphology and size distribution of the Au nanodisks and nanoholes were examined with scanning electron microscopy (SEM) and atomic force microscopy (AFM). The sensitivity of the localized surface plasmon resonance (LSPR) of the Au nanodisk arrays to change in the surroundings’ refractive index was evaluated by integrating the Au nanodisk arrays into microfluidic channels. In addition, we show that the NSL-fabricated Au nanohole arrays can be applied as templates for patterning micro-/nano-particles under capillary force. The unique structural and optical characteristics of the Au nanodisk and nanohole arrays, as well as the low-cost and high-throughput of NSL-based nanofabrication technique, render these arrays excellent platforms for numerous engineering applications.


Author(s):  
V. Izquierdo-Roca ◽  
J. Alvarez-Garcia ◽  
A. Perez-Rodriguez ◽  
L. Calvo-Barrio ◽  
A. Romano-Rodriguez ◽  
...  

1989 ◽  
Vol 7 (4) ◽  
pp. 251-261
Author(s):  
Takashi Horigome ◽  
Hiroshi Sugimoto

Solar energy development at the New Energy and Industrial Technology Development Organization (NEDO) is concerned with reducing the cost of photovoltaic (PV) systems by promoting low cost, high efficiency solar cell manufacturing technology and photovoltaic system demonstations. The first involves reducing the cost of solar cell modules by producing better silicon materials and improving fabrication techniques. A number of demonstration systems are in operation.


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