CdS/CdTe Heterostructures for Applications in Ultra-Thin Solar Cells

The preparation of ultra-thin semi-transparent solar cells with potential applications in windows or transparent roofs entails several challenges due to the very small thickness of the layers involved. In particular, problems related to undesired inter-diffusion or inhomogeneities originated by incomplete coverage of the growing surfaces must be prevented. In this paper, undoped SnO2, CdS, and CdTe thin films with thickness suitable for use in ultra-thin solar cells were deposited with a radiofrequency (RF) magnetron sputtering technique onto conductive glass. Preparation conditions were found for depositing the individual layers with good surface coverage, absence of pin holes and with a relatively small growth rate adapted for the control of very small thickness. After a careful growth calibration procedure, heterostructured solar cells devices were fabricated. The influence of an additional undoped SnO2 buffer layer deposited between the conductive glass and the CdS window was studied. The incorporation of this layer led to an enhancement of both short circuit current and open circuit voltage (by 19 and 32%, respectively) without appreciable changes of other parameters. After the analysis of the cell parameters extracted from the current-voltage (I-V) curves, possible origins of these effects were found to be: Passivation effects of the SnO2/CdS interface, blocking of impurities diffusion or improvement of the band alignment.

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Study of Photoelectrochemical Solar Cell Using WSe2 Crystal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.665.330 ◽

2013 ◽

Vol 665 ◽

pp. 330-335 ◽

Cited By ~ 1

Author(s):

Ripal Parmar ◽

Dipak Sahay ◽

R.J. Pathak ◽

R.K. Shah

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Fill Factor ◽

Short Circuit ◽

Short Circuit Current ◽

Electrical Energy ◽

Open Circuit ◽

Cell Parameters ◽

Photoelectrochemical Solar Cell ◽

Photoelectrochemical Solar Cells

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.

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Solar Photovoltaic Cell Parameters Extraction Using Differential Evolution Algorithm

Proceedings ◽

10.3390/proceedings2020063043 ◽

2020 ◽

Vol 63 (1) ◽

pp. 43

Author(s):

Rachid Herbazi ◽

Youssef Kharchouf ◽

Khalid Amechnoue ◽

Ahmed Khouya ◽

Adil Chahboun

Keyword(s):

Solar Cells ◽

Differential Evolution ◽

Short Circuit ◽

Differential Evolution Algorithm ◽

Short Circuit Current ◽

Photovoltaic Cell ◽

Open Circuit ◽

Good Precision ◽

Cell Parameters ◽

Power Point

This work presents a method for extracting parameters from photovoltaic (PV) solar cells, based on the three critical points of the current-voltage (I-V) characteristic, i.e., the short-circuit current, the open circuit voltage and the maximum power point (MPP). The method is developed in the Python programming language using differential evolution (DE) and a three-point curve fitting approach. It shows a good precision with root mean square error (RMSE), for different solar cells, lower than to those cited in the literature. In addition, the method is tested based on the measurements of a solar cell in the Faculty of Science and Technology of Tangier (FSTT) laboratory, thus giving a good agreement between the measured data and those calculated (i.e., RMSE = 7.26 × 10−4) with fewer iterations for convergence.

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Effect of CdTe thickness reduction in high efficiency CdS/CdTe solar cells

MRS Proceedings ◽

10.1557/proc-668-h6.4 ◽

2001 ◽

Vol 668 ◽

Cited By ~ 8

Author(s):

Akhlesh Gupta ◽

I. Matulionis ◽

J. Drayton ◽

A.D. Compaan

Keyword(s):

Solar Cells ◽

High Efficiency ◽

Short Circuit ◽

Short Circuit Current ◽

Cdte Film ◽

Open Circuit ◽

Thickness Reduction ◽

X Ray Diffraction ◽

Cell Parameters ◽

Cdte Solar Cells

ABSTRACTHigh efficiency CdTe solar cells are typically grown with CdTe thicknesses from 3 to 15 μm, although the thickness required for 90% absorption of the incident irradiation at 800 nm is only ∼1 μm. In this paper, we present the effect of CdTe thickness reduction on the performance of CdS/CdTe solar cells in which both the CdS and CdTe films were grown by sputtering. We produced a series of cells with different CdTe thickness (from 0.5 to 3.0 μm), and held the CdS thickness and back-contact-processing constant. The effect of CdTe thickness reduction on the diffusion of CdS into CdTe was studied using optical absorption and x-ray diffraction techniques. Only slight decreases occur in open-circuit voltage, short-circuit current, and fill factor with decrease in CdTe film thickness to 1.0 μm. Almost 10% efficient cells were obtained with 1 μm CdTe. Below 1 μm, all cell parameters decrease more rapidly, including the red quantum efficiency.

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Preparation and Photovoltaic Properties of Flexible Dye-Sensitized Solar Cells

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.112 ◽

2011 ◽

Vol 306-307 ◽

pp. 112-115 ◽

Cited By ~ 1

Author(s):

You Zeng ◽

Li Jia Zhao ◽

Ying Zhen ◽

Fang Xiao Shi ◽

Yu Tong

Keyword(s):

Solar Cells ◽

Short Circuit ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Treatment Temperature ◽

Photovoltaic Properties ◽

Dye Sensitized ◽

Conductive Glass ◽

Sensitized Solar Cells

Flexible dye-sensitized solar cells (DSCs) were prepared by using carbon nanotube transparent conductive films (CNT-TCFs) as flexible substrates, and their photovoltaic properties were investigated as well. The flexible DSCs show typical photovoltaic characteristics with short-circuit current of 0.78 μA and open-circuit voltage of 1.48 mV, which was strongly influenced by heat-treatment temperature, type of dyes, and electrical resistivity. In light of their lighter weight and higher flexibility than conventional DSCs based on conductive glass substrates, the flexible DSCs have great potential as functional photoelectric components in many fields.

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Measured and Simulated Temperature Dependence of A-Si:H Solar Cell Parameters

MRS Proceedings ◽

10.1557/proc-426-19 ◽

1996 ◽

Vol 426 ◽

Author(s):

H. Stiebig ◽

Th. Eickhoff ◽

J. Zimmer ◽

C. Beneking ◽

H. Wagner

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Temperature Dependence ◽

Crystalline Silicon ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Cell Parameters ◽

Crystalline Silicon Solar Cells ◽

Device Modelling

AbstractIn contrast to the successful application of analytic equations to the current-voltage behaviour of crystalline silicon solar cells in the dark and under AM1.5 illumination, the description of a-Si:H solar cells parameters requires device modelling concepts taking the full set of semiconductor equations into account. This in particular holds for the explanation of the temperature dependence (225–400K) of experimentally determined a-Si:H p-i-n solar cell parameters. Device modelling calculations show that the observed decrease of the short circuit current at AM 1.5 with lower T is much more effected by the additional charge trapped in the tail states and recharging of defect states than by the broadening of the gap. The induced electric field distortion blocks the extraction of photo generated holes. The open circuit voltage Voc increases with lower T which is caused by the same trapping effect.

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Measured and Simulated Temperature Dependence of A-Si:H Solar Cell Parameters

MRS Proceedings ◽

10.1557/proc-420-855 ◽

1996 ◽

Vol 420 ◽

Cited By ~ 12

Author(s):

H. Stiebig ◽

Th. Eickhoff ◽

J. Zimmer ◽

C. Beneking ◽

H. Wagner

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Temperature Dependence ◽

Crystalline Silicon ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Cell Parameters ◽

Crystalline Silicon Solar Cells ◽

Device Modelling

AbstractIn contrast to the successful application of analytic equations to the current-voltage behaviour of crystalline silicon solar cells in the dark and under AM 1.5 illumination, the description of a-Si:H solar cells parameters requires device modelling concepts taking the full set of semiconductor equations into account. This in particular holds for the explanation of the temperature dependence (225-400K) of experimentally determined a-Si:H p-i-n solar cell parameters. Device modelling calculations show that the observed decrease of the short circuit current at AM 1.5 with lower T is much more effected by the additional charge trapped in the tail states and recharging of defect states than by the broadening of the gap. The induced electric field distortion blocks the extraction of photo generated holes. The open circuit voltage Voc increases with lower T which is caused by the same trapping effect.

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The Effect of Diatomite on the Photoelectric Properties of TiO2 Dye Sensitized Solar Cells

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.1452 ◽

2013 ◽

Vol 448-453 ◽

pp. 1452-1456

Author(s):

Jiang Biao Feng ◽

Ling Jun Hua ◽

Feng Jun Shan ◽

Zhi Gang Yan ◽

Guo Chao Qi

Keyword(s):

Solar Cells ◽

Short Circuit ◽

Composite Films ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Dye Sensitized ◽

Conductive Glass ◽

Photoelectric Properties ◽

Sensitized Solar Cells

Diatomite/TiO2 composite films were prepared with diatomite and P25 TiO2 nanoparticles on conductive glass substrates. The surface morphology and phase composition of the film were characterized with scanning electron microscopy (SEM) and X ray diffraction (XRD). It is concluded that diatomite doped into the film will form granular cores. Dye sensitized solar cells (DSSC) were fabricated with the diatomite/TiO2 composite film as anode, and the photoelectric properties of the cells were tested. Results show that the doping of diatomite can significantly increase the open circuit voltage and short circuit current of DSSC. Optimized photoelectric properties can be acquired as 1.3 percent diatomite doped in TiO2 film.

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CdTe-Based Thin Film Solar Cells: Past, Present and Future

Energies ◽

10.3390/en14061684 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1684

Author(s):

Alessandro Romeo ◽

Elisa Artegiani

Keyword(s):

Thin Film ◽

Solar Cells ◽

Solar Cell ◽

Short Circuit ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Early Years ◽

Solar Cell Efficiency ◽

Cell Efficiency

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.

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GaInP/GaAs/poly-Si Multi-Junction Solar Cells by in Metal Balls Bonding

Crystals ◽

10.3390/cryst11070726 ◽

2021 ◽

Vol 11 (7) ◽

pp. 726

Author(s):

Ray-Hua Horng ◽

Yu-Cheng Kao ◽

Apoorva Sood ◽

Po-Liang Liu ◽

Wei-Cheng Wang ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Low Temperature ◽

Triple Junction ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Metal Line ◽

Solar Simulator ◽

Junction Solar Cell

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.

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Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Energies ◽

10.3390/en14144268 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4268

Author(s):

Jessica de Wild ◽

Gizem Birant ◽

Guy Brammertz ◽

Marc Meuris ◽

Jef Poortmans ◽

...

Keyword(s):

Surface Roughness ◽

Solar Cells ◽

Short Circuit ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Electron Microscopic ◽

Current Increase ◽

Time Resolved ◽

Cigs Solar Cells

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

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