The document summarizes a seminar presentation on quantum dots solar cells. It begins with an introduction to the history of solar cells, from early experiments in the late 1800s to modern developments. It then discusses quantum dots, describing them as semiconductor nano crystals that can be tuned to different bandgap energies depending on their size. The document outlines different classifications of solar cells and compares the advantages and disadvantages of monocrystalline, polycrystalline, and thin film solar cells. Finally, it discusses coating techniques used to apply quantum dots, such as spin coating, spray coating, and blade coating, and why quantum dots are promising for improving solar cell performance.

1. A Seminar Presentation
On
MAULANA AZAD
NATIONAL INSTITUTE OF TECHNOLOGY
BHOPAL
Presented by-Nitin
Paliwal

2. 1.Introduction
2.History of Solar cell
3.Use of Quantum dots
4.Solar cell Classification
5.Coating Techniques

3. 1. 1888 – Russian physicist Aleksandr Stoletov built the first
cell based on the outer photoelectric effect discovered
by Heinrich Hertz in 1887.[6]
2. 1904 – Julius Elster, together with Hans Friedrich Geitel,
devised the first practical photoelectric cell
3. 1905 – Albert Einstein proposed a new quantum theory of
light and explained the photoelectric effect in a landmark
paper, for which he received the Nobel Prize in Physics in
1921.
4. 1941 – Vadim Lashkaryov discovered p-n-junctions
in Cu2O and Ag2S protocells
5. 1946 – Russell Ohl patented the modern junction
semiconductor solar cell,[10] while working on the series of
advances that would lead to the transistor
6. 1948 - Introduction to the World of
Semiconductors states Kurt Lehovec may have been the first
to explain the photo-voltaic effect in the peer reviewed
journal Physical Review.
7. 1954 – The first practical photovoltaic cell was publicly
demonstrated at Bell Laboratories.[13] The inventors
were Calvin Souther Fuller, Daryl Chapin and Gerald Pearson
8. 1958 – Solar cells gained prominence with their incorporation

4. Quantum dots are semiconductor Nano crystals.
They are made of the same materials as ordinary
semiconductors (mainly combinations of transition
metals and /or metalloids).
Unlike ordinary bulk semiconductors, which are
generally macroscopic objects, quantum dots are
extremely small, on the order of few
nanometres. They are very nearly zero-
dimensional
WHAT IS A QUANTUM DOT ?

6. Solar cell
classification
• First generation(Mono-
crystalline)- single crystals of
pure silicon.
• Second generation(Poly-
crystalline)- Several crystals
of silicon
• Third generation(Thin film)-
A thin-film solar panel is
made of thin films of
semiconductors deposited on
glass , plastic or metels.

7. Advantages and disadvantage of Mono-
crystalline
Advantages
• Among all solar panel types,
monocrystalline cells have the
highest efficiency typically in the
15-20% range.
• As this solar panel is more
efficient so it produces more
power.
• These are having greater heat
resistance.
• In case of low level of sunlight, it
can make power.
• Monocrystalline solar cells can be
recycled. As it is made of 3 main
components i.e. monocrystalline
cells, Glass and Metal. These are
all can recycle.
Disadvantage
• These are most
expensive.
• Most monocrystalline
solar cells have a
temperature coefficient
of around -0.3%C to -
0.5%C. So when the
temperature rises, the
monocrystalline solar cell
will temporarily lose
0.3% to 0.5% of its
efficiency.
• There is a lot of waste

8. Advantages and Disadvantage of Poly-Crystalline Solar
cells
•The manufacturing process
of these panels are cheaper
and easier than the
monocrystalline cells.
•These panels have high
power density.
•During its manufacturing
process, it avoids silicon
wastes and requires very few
fossil fuels.
•These are more eco-friendly
•These are less efficient
between 13%-16%.
•It has lower output
rate.
•It needs more roof
space for installation.
•They damage easily
when exposed to high
temperatures.
Advantages Disadvantage

9. Advantage and Disadvantage of thin
film solar cell.
Advantage
• It is very flexible and can
be applicable to a range of
situations and building
types.
• Large no of production is
easy to achieve, making
them potentially cheaper
to produce than crystalline
solar cells.
Disadvantage
s
• As they take up a lot of
space so it is not good for
domestic use.
• It has low efficiency.
• It has shorter lifespan and
so shorter warranty
periods.

10. Parameters Mono Poly Thin-film
Efficiency 15%-20% 13%-16% 5%-10%
Materials used Single crystal of silicon Several crystal of silicon Amorphous si(thin Si
layer)
Life span 25-30yr 20-25yr 15-20yr
Weight per m^2 Higher Higher Lower
High temp. performances Drops 10-15% Drops 20% Drops 0%
Cost More Expansive Less Expansive Less Expensive

11. Why Quantum dots solar cell’s
• The enhancement of solar cell performance in the infrared region is an important
challenge to develop high efficiency solar cells.
• PbS quantum dots (CQDs) are a promising constituent material for solar cells since
quantum confinement effects yield unique optical and electrical properties.
 High degree of freedom for controlling exciton absorption band positions.
 CQD solid films give a relatively high carrier mobility.
 Compatible with low-temperature, solution-based technology.

12. Why use a Pbs Quantum
dot? 1. Quantum dot (QD) solar
cells have the potential to
increase the maximum
attainable thermodynamic
conversion efficiency of
solar photon conversion up
to about 66% by utilizing
hot photogenerated
carriers to produce higher
photovoltages or higher
photocurrents.

13. Colloidal quantum dots
(QDs) have been widely
studied as absorbers for
various solar technologies
because of their excellent
optoelectronic properties,
such as a size-dependent
absorption spectrum,
efficient charge separation
and transport, and good
photostability
Solution processed coating and printing techniques Spin coating, Dip
coating, Spray coating, Slot-die, Inkjet et.al,
Solution processed synthesis PbS QD and deposition QD
film"

14. Semiconductor Structures Exciton Bhor Radius (nm) Bandgap Energy (eV)
PbS 40.0 0.41
GaAs 28.0 1.43
CdTe 15.0 1.50
CdSe 10.6 1.74
ZnSe 8.4 2.58
CdS 5.6 2.53

15. Coating
Techniques
1.Spin coating method
2.Spray coating method
3.Blade coating

16. Spin coating is a method to apply a uniform film
onto a solid surface by using centrifugal force and
requires a liquid–vapor interface. In a typical
procedure, a liquid is placed at the center of a
circular surface and is rapidly rotated to produce
uniform films of 1–10 μm in thickness.
SPIN COATING METHODS

17. LITERATURE SURVEY
S.n
o
Name of the
Author/Author’s
Title of the
paper
Summary Remark
1. Yin-Fen Ma, You-Mei
Wang, Jia Wen, Ao Li,
Xiao-Liang Li, Mei Leng,
Yong-Biao Zhao, Zheng-
Hong Lu
Review of roll-
to-roll
fabrication
techniques for
colloidal quantum
dot solar cells
This paper reviewed recent studies on the
fabrication of large-area CQD solar cells with
various roll-to-roll compatible techniques.
Amongst, spray coating and blade coating are
shown to be promising Journal Pre-proof for
producing high-performance CQD solar cells.
While other coating techniques, including slot-
die coating and dip coating, which have been
used for perovskite and organic solar cells, do
not attracted much attention in the field of
CQD solar cells. The performance of CQD
solar cells based on those methods is still low
compared with that of other solution-
processed technologies, such as perovskite and
organic solar cells. There is still a long way to
go. However, CQDs are also promising for
solar cell applications
stract Colloidal
quantum dots (CQDs)
are of great interest
for photovoltaic (PV)
technologies as they
possess the benefits
of solution-
processability, size-
tunability, and roll-
to-roll
manufacturability, as
well as unique
capabilities to harvest
near-infrared (NIR)
radiation
2. Saim Emin ⇑ , Surya P.
Singh 1 , Liyuan Han ⇑ ,
Norifusa Satoh 1 ,
Ashraful Islam
Colloidal quantum
dot solar cells
Here we reviewed the recent
advances in utilizing colloidal
quantum dots as light harvesters
in various types of photovoltaic
devices. At present the power
conversion efficiencies of colloidal
quantum dot solar cells are about
In Abstract In recent
years colloidal quantum
dots solar cells have
been the subject of
extensive research. A
promising alternative to
existing silicon solar
cells, quantum dot solar

18. 3. Jung Hoon Song1 and Sohee Jeong Colloidal
quantum dot
based solar
cells:
from materia
ls to devices
CQDs have been
attracting much
attention because
they can absorb light
above their energy
bandgap with a high
extinction coefcient
and can be processed
by using a solution
process.
idal quantum dots
(CQDs) have
attracted attention as
a next-generation of
photovoltaics (PVs)
capable of a tunable
band gap and low-cost
solution process.
Understanding and
controlling the surface
of CQDs lead to the
signifcant development
in the performance of
CQD PVs
4. Khalil Ebrahim Jasim
Department of Physics,
College of Science,
University of Bahrain,
Kingdom of Bahrain
Quantum Dots
Solar Cells
Crystalline
semiconductor solar
cells besides
possessing low
efficiency due to
their band gab limit
(Shockley-Queisser
limit)[53] they are
expensive in terms of
manufacturing cost
per generated Watt

19. Reference
s
1. Yin-Fen Ma, Review of roll-to-roll fabrication techniques for colloidal quantum dot solar
cells, https://doi.org/10.1016/j.jnlest.2023.100189
2. Jung Hoon Song and Sohee Jeong, Colloidal quantum dot based solar cells: from materials
to devices, https://doi.org/10.1186/s40580-017-0115-0
3. Saim Emin, Colloidal quantum dot solar cells, https://doi.org/10.1016/j.solener.2011.02.005
4. Khalil Ebrahim Jasim, Quantum Dots Solar Cells, http://dx.doi.org/10.5772/59159
5. https://en.wikipedia.org/wiki/Solar_cell
6. https://solarismypassion.com/solar-blogs/type-of-solar-
panels/?_gl=1*dflo9u*_ga*V0c1RFFHX1N1UHRpa3Etc2N3MGo5QURINkwzWWRPZVJ
CSzRaMXZrRzBhVGZ5dUtCSkN4SVhTSmlrWWpYT25Uag
7. https://www.solarsquare.in/blog/types-of-solar-panels

20. Reference
s