Preparation of Narrow-gap a-Si:H Solar Cells by VHF-PECVD Technique

2010 ◽  
Vol 1245 ◽  
Author(s):  
Do Yun Kim ◽  
Ihsanul Afdi Yunaz ◽  
Shunsuke Kasashima ◽  
Shinsuke Miyajima ◽  
Makoto Konagai

AbstractOptical, electrical and structural properties of silicon films depending on hydrogen flow rate (RH), substrate temperature (TS), and deposition pressure (PD) were investigated. By decreasing RH and increasing TS and PD, the optical band gap (Eopt) of silicon thin films drastically declined from 1.8 to 1.63 eV without a big deterioration in electrical properties. We employed all the investigated Si thin films for p-i-n structured solar cells as absorbers with i-layer thickness of 300 nm. From the measurement of solar cell performances, it was clearly observed that spectral response in long wavelength was enhanced as Eopt of absorber layers decreased. Using the solar cell whose Eopt of i-layer was 1.65 eV, the highest QE at long wavelength with the short circuit current density (Jsc) of 16.34 mA/cm2 was achieved, and open circuit voltage (Voc), fill factor (FF), and conversion efficiency (η) were 0.66 V, 0.57, and 6.13%, respectively.

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.


2011 ◽  
Vol 378-379 ◽  
pp. 601-605 ◽  
Author(s):  
Saleh N. Alamri ◽  
M. S. Benghanem ◽  
A. A. Joraid

This study investigates the preparation of the three main layers of a CdS/CdTe thin film solar cell using a single vacuum system. A Close Space Sublimation System was constructed to deposit CdS, CdTe and CdCl2 solar cell layers. Two hot plates were used to heat the source and the substrate. Three fused silica melting dishes were used as containers for the sources. The properties of the deposited CdS and CdTe films were determined via Atomic force microscopy, scanning electron microscopy, X-ray diffraction and optical transmission spectroscopy. An J-V characterization of the fabricated CdS/CdTe solar cells was performed under solar radiation. The short-circuit current density, Jsc, the open-circuit voltage, Voc, fill factor, FF and conversion efficiency, η, were measured and yielded values of 27 mA/cm2, 0.619 V, 58% and 9.8%, respectively.


2018 ◽  
Vol 32 (02) ◽  
pp. 1850014 ◽  
Author(s):  
G. S. Sahoo ◽  
G. P. Mishra

Recent trends of photovoltaics account for the conversion efficiency limit making them more cost effective. To achieve this we have to leave the golden era of silicon cell and make a path towards III–V compound semiconductor groups to take advantages like bandgap engineering by alloying these compounds. In this work we have used a low bandgap GaSb material and designed a single junction (SJ) cell with a conversion efficiency of 32.98%. SILVACO ATLAS TCAD simulator has been used to simulate the proposed model using both Ray Tracing and Transfer Matrix Method (under 1 sun and 1000 sun of AM1.5G spectrum). A detailed analyses of photogeneration rate, spectral response, potential developed, external quantum efficiency (EQE), internal quantum efficiency (IQE), short-circuit current density (J[Formula: see text]), open-circuit voltage (V[Formula: see text]), fill factor (FF) and conversion efficiency ([Formula: see text]) are discussed. The obtained results are compared with previously reported SJ solar cell reports.


2015 ◽  
Vol 761 ◽  
pp. 341-346 ◽  
Author(s):  
Ahmad Aizan Zulkefle ◽  
Maslan Zainon ◽  
Zaihasraf Zakaria ◽  
Mohd Ariff Mat Hanafiah ◽  
Nurul Huda Abdul Razak ◽  
...  

This paper presents the performance between silicon germanium (SiGe) and crystalline germanium (Ge) solar cells in terms of their simulated open circuit voltage, short circuit current density, fill factor and efficiency. The PC1D solar cell modeling software has been used to simulate and analyze the performance for both solar cells, and the total thickness is limited to 1μm of both SiGe and Ge solar cells. The Si0.1Ge0.9 thickness is varied from 10nm to 100nm to examine the effect of Si0.1Ge0.9 thickness on SiGe solar cell. The result of simulation exhibits the SiGe solar cell give a better performance compared to Ge solar cell. The efficiency of 9.74% (VOC = 0.48V, JSC = 27.86mA/cm2, FF =0.73) is achieved with Si0.1Ge0.9 layer of 0.1μm in thickness whilst 2.73% (VOC = 0.20V, JSC = 27.31mA/cm2, FF =0.50) efficiency is obtained from Ge solar cell.


2012 ◽  
Vol 260-261 ◽  
pp. 154-162
Author(s):  
S. Tobbeche ◽  
M.N. Kateb

In this work, we present the simulation results of the technological parameters and the electrical characteristics of a crystalline silicon n+pp+ solar cell, using two-dimension (2D) software, namely TCAD Silvaco (Technology Computer Aided Design). TCAD Silvaco Athena is used to simulate various stages of the technology manufacturing, while TCAD Silvaco Atlas is used for the simulation of the electrical characteristics and the spectral response of the solar cell. The J-V characteristics and the external quantum efficiency (EQE) are simulated under AM 1.5 illumination. The conversion efficiency(η)of 16.06% is reached and the other characteristic parameters are simulated: the open circuit voltage (Voc) is of 0.63 V, the short circuit current density (Jsc) equals 30.54 mA/cm² and the form factor (FF) is of 0.83 for the n+pp+ solar cell with a silicon nitride antireflection layer (Si3N4). In order to highlight the importance of the back surface field (BSF), a comparison between two cells, one without BSF (structure n+p), the other with one BSF (structure n+pp+), was made. By creating a BSF on the rear face of the cell the short circuit current density increases from 28.55 to 30.54 mA/cm2, the open circuit voltage from 0.6 to 0.63 V and the conversion efficiency from 14.19 to 16.06%. A clear improvement of the spectral response is obtained in wavelengths ranging from 0.65 to 1.1 µm for the solar cell with BSF.


MRS Advances ◽  
2019 ◽  
Vol 4 (37) ◽  
pp. 2035-2042 ◽  
Author(s):  
L.A. Rodríguez-Guadarrama ◽  
I.L. Alonso-Lemus ◽  
J. Campos-Álvarez ◽  
J. Escorcia-García

ABSTRACTTernary Sn-Sb-S thin films with remarkable optical, electrical and structural properties were developed by chemical bath deposition. Tin and antimony chlorides and thioacetamide were used as tin, antimony, and sulfur ion sources, respectively, while tartaric acid was used as a complexing agent. XRD analysis of as-deposited films showed a combination of binary phases of SnS, Sn2S3, and Sb2S3, while after thermal treatment in nitrogen at 400 °C, the films became crystalline showing well-defined reflections of the ternary SnSb2S4. The heating also influenced the morphology, compactness, and thickness of the films. On the other hand, all the films showed an absorption coefficient higher than 104 cm-1, while the optical band gap of the as-deposited film decreased from 1.49 to 1.37 eV after heating at 400 °C. In addition, the photoconductivity of the films prior to heating was of 10-9 Ω-1 cm-1, while after that at 400 °C was of 10-7 Ω-1 cm-1. The evaluation of the ternary film in solar cells gave an open-circuit voltage Voc of 448 mV and short-circuit current density of Jsc of 2.4 mA/cm2.


2004 ◽  
Vol 808 ◽  
Author(s):  
Chunhai Ji ◽  
Wayne A. Anderson

ABSTRACTThe poly-Si film was deposited by using the metal-induced growth (MIG) method on tungsten substrates. By making Au/n-Si Schottky photo-diodes, doping density effect was studied by using three different doping level Si sputtering targets. Increasing the Si target resistivities from 0.02Ω-cm to 50Ω-cm, open-circuit-voltage (Voc) decreased from 0.22V to 0.14V while short-circuit-current density (Jsc) increased from 1.55mA/cm2 to 2.42mA/cm2. C-V results revealed a high charge density in the device, which may be due to the oxygen thermal donor effects. Using an oxygen filter for the sputtering gas effectively reduced the charge densities and increased the Jsc value. The p/n junction solar cells were fabricated by using ion implantation at 1013∼1014cm−2 dose and 100∼200keV. The cells with wider emitter layer by double-ion implantation gave higher Jsc and Voc values. Passivation of the Si film by using hydrogenation improved the Jsc, Voc and spectral response of the solar cells.


2014 ◽  
Vol 1670 ◽  
Author(s):  
José Escorcia-García ◽  
Enue Barrios-Salgado ◽  
M.T.S. Nair ◽  
P.K. Nair

ABSTRACTWe report a stable CdS/Sb2S3/SnSe heterojunction thin film solar cell deposited on SnO2:F (FTO) – coated glass substrates. Thermal evaporation at 10-5 Torr with substrate temperature of 400 °C was used to deposit Sb2S3 and SnSe thin films of 450 nm and 160 nm, respectively. Thin film Sb2S3 has an optical band gap (Eg) of 1.48 eV and photoconductivity (σp) of 4x10-7 Ω-1 cm-1 and thin film SnSe has an Eg of 1.28 eV and σp of 2 Ω-1 cm-1. The chemically deposited CdS thin film heated at 400 °C shows an Eg of 2.34 eV and σp of 0.1 Ω-1 cm-1. Stabilized solar cell structures with these thin films, FTO/CdS/Sb2S3/SnSe/C-Ag, showed open circuit voltage (Voc) of 0.60 V, short circuit current density (Jsc) of 5.51 mA/cm2 and power conversion efficiency (η) of 0.96% with a fill factor FF of 0.29. In the absence of the SnSe layer, Jsc decreases to 4.77 mA/cm2.


Author(s):  
Rachid Chaoui ◽  
Bedra Mahmoudi ◽  
Yasmine Si Ahmed

Stain etching of silicon solar cells in HF-FeCl3-H2O solutions as a last step in the processing sequence is reported. The etching was carried out without protecting the screen printed contacts. Following optimization of the solution composition and using very short etching times to alleviate the contact degradation problem, the solar cell weighted reflectance (Rw) between 400 and 1100 nm could be reduced from 38.23% to 11.54%. For the best small area cell (~20 cm2), the PS antireflective layer led to a relative improvement of 62.74% in the short-circuit current density, the FF was enhanced by 5.5% absolute, the open-circuit voltage was increased by 1.2 mV and the cell conversion efficiency was raised by 4.1% absolute from 5.4% to 9.5%. The best large area cell (~78 cm2) shows the following changes after porous layer formation: a relative improvement of 45.43% in the short-circuit current density, an improvement in the FF of 7.4% absolute, an increase in the open-circuit voltage by 7.5 mV and an enhancement in the cell efficiency by 4.0% absolute from 6.2% to 10.2%. This method shows a great potential for the cost-effective reduction of reflectance losses in industrial silicon solar cell manufacturing.


2018 ◽  
Vol 36 (3) ◽  
pp. 514-519
Author(s):  
Bechlaghem Sara ◽  
Zebentout Baya ◽  
Benamara Zineb

AbstractThe purpose of this work is to achieve the best efficiency of Cu(In, Ga)Se2 solar cells by replacing the CdS buffer layer with other nontoxic materials. The simulation tool used in this study is Silvaco-Atlas package based on digital resolution 2D transport equations governing the conduction mechanisms in semiconductor devices. The J-V characteristics are simulated under AM1.5G illumination. Firstly, we will report the modeling and simulation results of CdS/CIGS solar cell, in comparison with the previously reported experimental results [1]. Secondly, the photovoltaic parameters will be calculated with CdS buffer layer and without any buffer layer to understand its impact on the output parameters of solar cells. The simulation is carried out with the use of electrical and optical parameters chosen judiciously for different buffers (CdS, ZnOS and ZnSe). In comparison to simulated CdS/CIGS, the best photovoltaic parameters have been obtained with ZnOS buffer layer. The structure has almost the same open circuit voltage Voc and fill factor FF, and higher short circuit current density Jsc, which results in slightly higher conversion efficiencies.


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