Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
Xiaoxing xi progress in the investigation of mg b2 thin films for srf cavit...thinfilmsworkshop
MgB2 thin films grown by hybrid physical-chemical vapor deposition (HPCVD) have been investigated for SRF cavity applications. I will present our recent results of research in three directions: enhancement of Hc1 in thin MgB2 films, large area MgB2 films on Cu, and the effort on coating of RF cavities. By reducing the thickness of the MgB2 film from 300 nm to 100 nm, Hc1(0) increases systematically from 38 mT to about 200 mT in both epitaxial and polycrystalline films. The HPCVD process has been successfully applied on 2” diameter Cu substrate. Both the in-situ and two-step processes have been used for the coating of a 6 GHz cavity. Samples from various locations of the cavity show good superconducting properties. Effort is underway to coat 3 GHz RF cavities.
graphene, a wonder material, is useful in many areas.it is multifunctional.till now it is said to be harmless.it is a sure one that graphene is the future of science.scientists have found many applications of graphene and the research goes on.it is said ti have limitless functions.its peculiar properties makes itself unique and efficient.it is eco friendly as it is biodegradable
Structural, Optical and Electrical Studies on Spray Deposited Mercury Doped C...ijrap
Thin films of cadmium sulphide have been prepared using home built spray pyrolysis unit on glass substrate at 400 C. Aqueous solutions of cadmium chloride and thiourea were used for the cadmium
sulphide (CdS) films and different proportions by weight/volume of mercury II chloride was used for doping Hg onto cadmium sulphide (Cd1-xHgxS) films. The films obtained are having continuous, smooth surface with good transmittance. The thickness of all films is of the order of 320 nm. Determination of the crystalline nature has been done using XRD pattern. The effect of Hg on the surface morphology of CdS film has been studied by Scanning Electron Microscopy. The optical band gap has been calculated using the data from transmission spectra. Resistance before and after doping with Hg is also presented in the paper.
Xiaoxing xi progress in the investigation of mg b2 thin films for srf cavit...thinfilmsworkshop
MgB2 thin films grown by hybrid physical-chemical vapor deposition (HPCVD) have been investigated for SRF cavity applications. I will present our recent results of research in three directions: enhancement of Hc1 in thin MgB2 films, large area MgB2 films on Cu, and the effort on coating of RF cavities. By reducing the thickness of the MgB2 film from 300 nm to 100 nm, Hc1(0) increases systematically from 38 mT to about 200 mT in both epitaxial and polycrystalline films. The HPCVD process has been successfully applied on 2” diameter Cu substrate. Both the in-situ and two-step processes have been used for the coating of a 6 GHz cavity. Samples from various locations of the cavity show good superconducting properties. Effort is underway to coat 3 GHz RF cavities.
graphene, a wonder material, is useful in many areas.it is multifunctional.till now it is said to be harmless.it is a sure one that graphene is the future of science.scientists have found many applications of graphene and the research goes on.it is said ti have limitless functions.its peculiar properties makes itself unique and efficient.it is eco friendly as it is biodegradable
This paper explains the fabrication of thin film using modified Physical Vapor Deposition (PVD) Module. Physical Vapor Deposition (PVD) is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit thin films by the condensation of a vaporized form of the material onto various surfaces. The surface morphology of various such as Titanium Dioxide and Aluminum thin film has been studied. The Titanium Dioxide and Aluminum thin film has been fabricated on Silicon (Si) substrate using modified Physical Vapor Deposition (PVD) module system. The process started with the establishment of process flow, process modules, and process parameters. Two modules were developed. The characteristics prior to the thin film fabrication namely surface morphology, metal thickness characterization and V-I characteristic were recorded. The samples were characterized by Optical Microscope, Atomic Force Microscope (AFM),X-ray diffraction (XRD) and I - V characterization. The result and data were analyzed and applied in the fabrication of thin film using various materials. The thin film fabrication process used Titanium Dioxide (TiO2) nanopowder and Aluminum (Al2O3) nanopowder for the coating process. The result for each processes are presented in this paper.
Different Generation Solar Cells
CIGS and CZTS Based Technology
Ink Based Technology
CIGS Device Structure
Making more efficient solar cells
Developing thin film technologies using alternative less costly materials and methods
Incorporate innovative cheaper deposition methods such as electrodeposition and printing technology
Huge demand of silicon in photovoltaic cells caused a shortage of silicon which results in demand
for new technology in this field and so another revolutionary cheap method is innovated namely thin film solar
cell. In this paper, various types of thin film solar cells are reviewed. They have less efficiency and also low cost
compared to 1st generation solar cell. They are based on silicon Thin film implies that less material is used
which makes the solar cells cheaper.
Characterization Studies of CdS Nanocrystalline Film Deposited on Teflon Subs...IJLT EMAS
In this article, different substrates for deposition of
CdS material have been discussed. Till date glass, mica, quartz,
ceramic, etc. are commonly employed substrates in thin film
growth. In the present work, CdS is deposited on Teflon
substrate by chemical bath deposition (CBD) method. Also the
films were deposited on different substrates like glass, copper
and zinc and compared with those prepared on Teflon substrate.
The films prepared on Teflon substrate were uniform, stable and
also showed good radiating property. These films were further
characterized by UV-VIS absorption spectral studies, SEM and
EDS studies.
Aluminum doped cadmium selenide tin films of different compositions, (0.1-1.0 mol %) deposited by dip
coating method on cleaned glass substrates at room temperature. All the films are polycrystalline nature
having hexagonal structure. For all the films the preferred orientation is (100). Some other orientations like
(101), (110), (112) (202) (203) are also observed in the films. The values of interplanar distance, dislocation
density, microstrain, lattice parameters, volume of unit cell, number of crystallites per unit area and particle
size of the aluminum doped thin films were calculated and their variation with dopant concentration was
studied. Interplanar distance, intensity, lattice parameters, volume of unit cell and particle size increases up
to 0.25mol % of aluminum. Microstrain, dislocation density and number of crystallite per unit area decreases
up to 0.25mol % aluminum concentration
CIGS Solar Cells: How and Why is their Cost Falling?Jeffrey Funk
My master's students use concepts from my (Jeff Funk) forthcoming book (Technology Change and the Rise of New Industries) to analyze the economic feasibility of CIGS (Cadmium Indium Gallium Selenide) Solar Cells. Improvements in efficiencies and reductions in cost per area (through new processes and increasing the substrate size) are causing steady reductions in the cost of electricity from them. See my other slides for details on concepts, methodology, and other new industries..
Morphological and Optical Study of Sol-Gel SpinCoated Nanostructured CdSThin ...iosrjce
Nanostructured CdS thin films of different thicknesses were deposited on a cleaned glass substrate
using sol-gel spin coating technique. CdS thin films were prepared using cadmium acetate as cadmium source
and thiourea as sulfur source. The Morphological, chemical composition, and optical properties of the spin- coated
CdS thin film were studied using field emission- scanning electron microscopy (FE-SEM), Energy dispersive X –ray
(EDX) spectroscopy, and a UV-Vis-NIR spectrophotometer.The morphological results revealed that the films consist
of agglomerated spherical CdS nanoparticles with diameter < 20 nm, which distributed uniformly on the substrate
surface.The films show high transmittance > 90% and very strong absorption edge at 295 nm.The absorption edge
shifts towards longer wavelength as the film thickness increased.
On the 21st of August 2020, IEEE Student Branch Chittagong University arranged a webinar on “Thin film solar cell research and manufacturing“
In this webinar, the effect of thin film on the solar panel construction was discussed broadly.
A low-cost non-toxic post-growth activation step for CdTe solar cellsUniversity of Liverpool
Cadmium telluride, CdTe, is now firmly established as the basis for the market-leading thin-film solar-cell technology. With laboratory efficiencies approaching 20 per cent1, the research and development targets for CdTe are to reduce the cost of power generation further to less than half a US dollar per watt (ref. 2) and to minimize the environmental impact. A central part of the manufacturing process involves doping the polycrystalline thin-film CdTe with CdCl2. This acts to form the photovoltaic junction at the CdTe/CdS interface3, 4 and to passivate the grain boundaries5, making it essential in achieving high device efficiencies. However, although such doping has been almost ubiquitous since the development of this processing route over 25 years ago6, CdCl2 has two severe disadvantages; it is both expensive (about 30 cents per gram) and a water-soluble source of toxic cadmium ions, presenting a risk to both operators and the environment during manufacture. Here we demonstrate that solar cells prepared using MgCl2, which is non-toxic and costs less than a cent per gram, have efficiencies (around 13%) identical to those of a CdCl2-processed control group. They have similar hole densities in the active layer (9 × 1014 cm−3) and comparable impurity profiles for Cl and O, these elements being important p-type dopants for CdTe thin films. Contrary to expectation, CdCl2-processed and MgCl2-processed solar cells contain similar concentrations of Mg; this is because of Mg out-diffusion from the soda-lime glass substrates and is not disadvantageous to device performance. However, treatment with other low-cost chlorides such as NaCl, KCl and MnCl2 leads to the introduction of electrically active impurities that do compromise device performance. Our results demonstrate that CdCl2 may simply be replaced directly with MgCl2 in the existing fabrication process, thus both minimizing the environmental risk and reducing the cost of CdTe solar-cell production.
Thin films of cadmium sulphide have been
successfully deposited by chemical bath deposition (CBD)
technique using a mixed aqueous solution of cadmium
sulphate, thiourea, and triethylamine. The films were
characterized using a variety of techniques. Powder X-ray
diffraction analysis shows that the as-deposited thin film has
the hexagonal (wurtzite) structure. Scanning electron
microscope (SEM) micrographs show the film surface consists
of clusters with a globular surface morphology. Energy
dispersive X-ray diffraction (EDAX) analysis confirmed the
film to be consistent with the formation of cadmium sulphide
on silica glass slide. The band gap, determined from optical
absorption spectroscopy, was 2.42 eV which is consistent with
other published results.
Enhancement of rate of heat transfer using nano fluidsSharathKumar528
Nano fluids as coolants and lubricants is still very primitive in technology. This presentation explores the future of nano fluids for enhanced heat transfer.
Engineering Project involving design,manufacturing, testing of Fins( Heat exchanger for 2 wheeler). An analysis of heat transfer on fins with various geometrical perforations.
Experimentation and analysis of heat transfer through perforated fins of diff...SharathKumar528
Engineering Project by Abhijath HB, Dashartha H S, Akshay Mohanraj and Sharath Kumar M S involving analysis of Fins( Heat exchanging extensions) with various geometrical perforations.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...
Ultra thin solar cell integration in bipv focus on cd te and cigs
1. ULTRA THIN SOLAR CELL INTEGRATION IN BIPV:
FOCUS ON CdTe AND CIGS
Introduction:
BIPV technology revolutionizes building from energy consumer to producer of energy.
Photovoltaic modules have a large potential to serve as building exteriors such as roof, faced
and skylight. BIPV also serve as weather protection, thermal insulation and look aesthetically
good on the buildings. BIPV Thin-film are solar cells that are basically thin layers of
semiconductor materials applied to a solid backing material. Thin films greatly reduce the
quantity of semiconductor required for each cell when compared to silicon wafers. and hence
lowers the cost of production of photovoltaic cells. According to the type of photo voltaic
material used, thin film solar cells are classified as
Amorphous silicon(a-si)
Thin film silicon(TF-Si)
Cadmium telluride(CdTe)
Copper-Indium-Selenide(CIS) or Copper-Indium-Gallium-selenide(CIGS)
Dye sensitized solar cell (DSC)
And other organic solar cells.[1]
Cost of these thin film solar panel are low as compared to the older silicon wafer cells. The
functioning of these solar cells is however like that of silicon wafer cells. There are flexible
arrangements of different layer that help produce thin cells. Amorphous silicon module has a
lower efficiency of 4-10% than mono or polycrystalline but they perform better at higher
temperature. The thickness of these cells varies few nanometers to micrometers. They are
used in huge sophisticated building integrated installation. Research projects that that thin
film production would reach 22,214MW by 2020.Also, BIPV allow some light for day
lighting and thus cooling.[1]
2. Comparison of efficiency:
Out of all the thin films amorphous silicon cell produces the least efficiency and has higher
levelized cost of electricity generation. CdTe and CIGS offer the best efficiency and there are
a lot of researches on enhancing the efficiency of the CdTe and CIGS by adapting various
chemical processes. The paper will cover the manufacturing and efficiency obtained by
newest methods so far. The integration of amorphous silicon is questionable since several
arrays of amorphous silicon is necessary to produce the same power when compared to CIGS
or CdTe.[2]
Growth of thin film industry over the years
Cell material Module efficiency Surface area for 1 KW
power
Mono- crystalline silicon 15-18 7-9
Poly crystalline silicon 13-16 8-9
Micro morph tandem(aμ-si) 6-9 9-12
Thin film copper indium di-
selenide (CIGS)
10-12 9-11
Thin film cadmium
telluride(CdTe)
9-11 11-13
Thin film amorphous
silicon(α-si)
6-8 13-20
Table illustrating and comparing the efficiencies of different solar cells
Cadmium Telluride serve as the right choice for BIPV or any configuration that involve
flexible panel installation.
3. Manufacturing methods of CdTe solar cell
CdTe are made in both substrate and superstrate. Commercial CdTe modules are made in
super state configuration and has highest efficiency till date. Roll to roll process made on
metal foils is widely used for substrate configured cells. Efficiency of up to 14% and 11.5%
have been reported previously for super state and substrate configuration respectively. CdS
thin film is suitable for window layer of CdS/CdTe solar cells. They have been manufactured
using varying techniques and is classified as chalcogenide semiconductor and is used in
CdS/CdTe solar cells. It is preferred widely due to its wide and direct band gap(2.4eV). It is
therefore best suited for junction effect of CdS/CdTe solar cells because of its n-type
material. CdS is fabricated by electro deposition, RF sputtering, Chemical vapor transport
and chemical bath deposition (CBD).[3] [4]
Case study 1:
CBD is widely used for manufacture of CdS thin film for commercial CdS/CdTe solar cells.
Closed spaced sublimation (CSS) of CdCl2 heat treatment helps in grain growth, improved
electrical properties in CdTe thin film. A research carried out by Department of Materials
Science and Engineering, Korea University, studying optical properties of CdS/CdTe solar
cell used substrate glass coated with SnO2:F thin film. The film used is transparent and
possess high thermal stability. CdS thin films grown in beaker and the substrate was
deposited for 20 min, solution bath system consists of magnetic stirrer and heating system.
Beaker is then immersed into silicon oil maintaining a temperature of 75o
C. [5]
Solution consisted of CdCl2(0.002M), thiourea (SC(NH2)2 (0.003M), NH4Cl (0.015M),
NH4OH(0.640M) and deionized water. PH of ammonia bath solution is at 11. CdCl2 is used
as Cadmium precursor and Thiourea as Sulphur precursor. Ammonia is used as complexing
agent, NH3 is used as buffer. After deposition, the substrate is cleaned using dilute Hcl. CdS
thin film absorb photons and decrease the conversion efficiency of CdS/CdTe solar cells.
The schematic diagram of the working of thin film solar cell[5]
4. Case study 2:
In another research CdS and CdTe are deposited at 260o
C on a commercial SnO2 coated 3
mm thick soda-lime glass by magnetron sputtering. The thickness of CdS and CdTe layers
chosen by them was 0.13nm and 2.3nm respectively. The thickness was varied from 0.6 to
1.28nm. SnO2/CdS/CdTe cell structure is treated in vapours of CdCl2 at 390o
C in the presence
of dry air for various time durations. Cu+ Au bilayer or Au only layer is used as back contact
through a mask to produce 0.15 cm2
area dot cells followed by diffusion in room air at 1500
C.
In the study it was found out that optimum treatment time occurred at about 10 min.[6]
IV curve
Quantum efficiency versus wavelength
160
140
120
100
80
60
40
20
0
-20
6micro meter CdTe
0.87micrometerCdTe
2.3 micro meter CdTe
1.28 micro meter CdTe
-0.5 5
VoltageV
1.150.0
0.6micro meter0.87micro meter1.28micro meter
Wavelength nm
900 1000800700600500400300
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
CurrentDensity(mA/cm2)
Quantumeffeciency
5. Quantum efficiency comparison between treated and untreated CdTe
CdS(μm CdTe(μm) CdCl2(μm) Back
contact(cu)
Back contact
diffusion(min)
VOC(mV) JSC(mA/cm2
) FF% n%
0.13 2.3 30 30 45 807 23.3 72.3 13
0.13 1.28 30 30 30 714 21.3 65.9 10
0.13 1.28 10 30 30 710 22.3 61.4 9.7
0.13 1.04 10 15 18 767 22.1 66.8 11.3
0.13 1.04 10 15 18 795 21.2 70.8 11.9
0.13 1.04 30 0 No diffusion 641 20.9 60.4 8.1
0.13 0.87 10 15 18 772 22.6 69.7 11.8
0.08 0.6 30 30 30 484 20.1 44.0 4.3
0.08 0.6 10 15 18 708 20.5 64.6 9.4
0.07 0.94 10 15 10 762 22.6 67.4 11.6
0.05 0.7 10 15 10 750 21.7 69.2 11.2
Summary of the experimentation
All the above data are obtained from [4] [3]
From the above graphs thickness can be substantially reduced without losing much
efficiency. Optimization of post- deposition CdCl2 treatment and back contact diffusion
conditions lead to achievement of 11.8% efficient cells with 0.87 micro meter CdTe which is
9% relative loss from that of standard 2.3micro meter CdTe 13% cell. 11.2% efficiency using
0.05 micro meter CdS and 0.7 micro meter CdTe contributes as the thinnest CdTe of highest
efficiency.
Case study 3:
In a research conducted at National Renewable Energy Laboratory, USA a record efficiency
of 16.4% was achieved for a flexible CdTe solar cell breaking the previous record of 14.05%
previously. In their research they sputtered CdS:O window layer and evaporated and rapidly
processed ZnTe:Cu/Au as back contact. CdS:O sputter process is oxygenated process adopted
for uniformity of window layer and thereby to enhance Short Circuit current (ISC). ZnTe:Cu
Voltage
1.510.5
No treatment
Anneline treated
0.12
0.1
0.08
0.06
0.04
0.02
0
-0.02
0
-0.04
-0.5
Currentdensity(A/cm2)
6. back contact followed by rapid thermal processing leads to an increase of open circuit
voltage(VOC) and higher fill factor.[6]
In this section we look at the manufacturing of the most efficient BIPV technology involving
CdTe solar cell doped with bilayers of SnO2:F(FTO, Fluorine Tin oxide) and undoped Sn02
(TO, tin oxide). Transparent conducting oxides are deposited at a substrate temperature of
550o
C by metal organic chemical vapour deposition(MOCVD). CdS:O layer is sputtered at
room temperature using hot pressed stoichiometric CdS target. Sputtering is also done at
ambient pressure of Argon with 6% oxygen volume at a pressure of 10mTorr(1.33Pascals).
Closed spaced sublimation (CSS)is used to deposit CdTe layer at substrate temperature of
6000
C and CdTe plate is maintained at 660o
C for 2.5 minutes. Vapour CdCl2 is obtained as a
device stack and is treated by CSS (Closed spaced sublimation) at 4000
C for 10 minutes.
0.05% bromine/ethanol is used for contact pre-etching. A back layer of ZnTe:Cu is deposited
by co-evaporation from ZnTe and Cu, followed by Au on to the unheated substrate. Gold(Au)
is then evaporated through a metal mask as the contact area.[7]
From the Research the below data is obtained and is compared with efficiency of regularly
manufactured CdTe devices.
Type of manufacturing Current density
JSC (mA/cm2
)
Open circuit
voltage
VOC(mV)
Fill factor Efficiency
Sputtered CdS:O 24.3 822 70.3 14.1%
Chemical bath deposition
CdS
25.5 831 77.4 16.4%
VoltagemV
10.80.60.40.20
2
1.5
1
0.5
0
IV CURVE
CurrentmA
7. Thickness of CdS:O layer 100nm
Willow glass dimension 100µm X38.1mmx38.1mm
Device Area 0.07025cm2
Irradiance 1000W/m2
VOC (Open Circuit Current
Voltage)
0.873V
ISC (Short Circuit Current) 1.8mA
JSC (Current Density) 25.5mA/cm2
FF (Fill factor) 0.774
Efficiency 16.42%
Test module parameters
Manufacture of CIGS:
CdS chemical deposition process for Cu(In,Ga)Se2 in a research conducted by National
Energy Lab, USA varied their deposition time(varying the thickness therefore ), bath
temperature and Cd+2
partial electrolyte treatment of Chalcopyrite absorber prior to CdS
deposition. Bath solution used in the their research is 366ml of DI H2O,65.2ml of
NH4OH(Ammonium hydroxide),28-30%, 50 ml of thiourea(1.5 NH2CSNH2). Cd+2
Partial
electrolyte treatment is performed at 800
C using the same bath solution but excluding
Thiourea. ZnO bilayer (I ZnO and n-ZnO) ZnO bilayer and contacts are completed after the
CBD treatment.
ChemicalbathdepositionCdSSputtered CdS:O
300 400 500 600 700 800 900
90
80
70
60
50
40
30
20
10
0
100
90
80
70
60
50
40
30
20
10
0
IQE vsWavelength
Quantumeffeciency%
8. 0
Growth of CdS in CdTe substrate in the left and internal quantum efficiency vs wavelength in
left
It was found that thinner CdS layer allowing more light to reach the junction was not
conductive to higher short circuit current. The research concludes that device parameters was
dependent on CdS layer thickness but independent of growth temperature. Cd+2
partial
electrolyte treatment was more susceptible to CdS thickness. Thus, thinner the CdS layer,
lesser the losses of parameters like VOC and FF. In general, thin layers of CdS provide a
better device performance. At optimum thickness highest performance is achieved, increasing
the JSC due to absorption in the buffer layer. The effect of increasing CdS thickness can be
seen in the range between 350-500nm.The effect of CdS layer thickness on the spectral
response modelled using absorption co-efficient of CIGS absorber is based on:
nq=1[1=1/α x L]
Where L is diffusion length
α is absorption coefficient.
CdS layer thickness effects IV characteristics as well. It can be seen in the reverse bias.
Breakdown effect called Zener effect results in tunnelling, with thicker CdS layers a larger
breakdown voltage is seen and this efficiency limits the amount of tunnelling taking place in
reverse bias. Cd incorporation and n-type doping effects are seen on the surface of CIGS.
This is seen in the improvements of VOC and FF. A standard CdS buffer layer grown at 650
C
for 15 min and no electrolyte treatment is chosen as standard and is compared to 5-15min
deposition of thinner CdS buffer layer. Although there is decrease in the FF, it is still better
than untreated layers of CdS. Cd+2
partial electrolyte in combination with thinner buffer layer
leads to increased current density JSC. It was illustrated in the research, comparing QE f
18.8% cell with QE of Cd+2
PI treated usingequation
JT=qx∫
∞
𝑛𝑞(dT/dλ)dλ
JT is currentdensity
Q is electron charge
Nq is internal quantum efficiency
9. dT/dλ is global solar spectrum (AM 1.5)
λ is wavelength.
Cd+2
provide additional 1.2mA/cm2
JSC value for wavelength <550nm. In addition CdS layers
builds a sufficient wide depletion width that minimizes tunnelling and establishes higher
contact potential (high VOC values). It also coats absorber surface minimizing voids at
metallurgical interface and provides electronic and metallurgical Junction protection against
subsequent sputter damage from ZnO window deposition.
Conclusion:
The several state-of-the-art buildings integrated photovoltaic (BIPV) merchandise current on
the market today provide a huge vary of integration of photovoltaic (PV) systems into
buildings.
Continued research and development within both PV and BIPV materials and applied
sciences will yield higher and better BIPV solutions within the years to come back, e.g.
with reference to multiplied photovoltaic cell potency, reduced production costs and
improved building integration. New and innovative solutions might cut back prices and
increase the market share, amongst different within the retrofitting market. The chosen
solutions ought to be simply applicable, wherever one example of a future vision is paint
applications of PV cells. it's crucial that everyone new technologies and solutions area
unit completely tested and approved in accordance with existing standards,
10. and moreover, there's conjointly a desire for development of recent standards and ways,
e.g. concerning long sturdiness versus climate exposure.
References.
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