Multijunction Photovoltaic Technologies for High Performance ...
Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction...
Transcript of Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction...
![Page 1: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/1.jpg)
Vanni Lughi Department of Engineering and Architecture, University of Trieste
Kreuzbergpass (BZ), Italy
June 17th – 21th, 2019
Photovoltaics Physics, current and emerging technologies
Summer School on Energy Giacomo Ciamician
![Page 2: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/2.jpg)
Fotovoltaico:
Conversione DIRETTA
di energia solare in energia elettrica
(gratis!)
![Page 3: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/3.jpg)
PV price reduction - example: rooftop PV installations in Germany -
![Page 4: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/4.jpg)
Germany
Role of Balance of System - The cost of BoS today is comparable with that of the modules -
BOS (including inverter)
Modules
![Page 5: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/5.jpg)
The role of BoS - In BoS, overall there is more margin for cost reduction -
Typical price of a 4kWp turnkey
domestic PV plant
![Page 6: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/6.jpg)
What kind of energy?
What role for photovoltaics?
What role for new technologies?
![Page 7: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/7.jpg)
Portable power The portable power market is just starting and needs new technology
![Page 8: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/8.jpg)
1.
Absorption of
solar radiation
Creation of
free carriers
2.
Free carrier
extraction
Electrical energy
Photovoltaic Effect
En
erg
y
+ -
![Page 9: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/9.jpg)
- +
Absorber’s Requirements: •Bandgap matched with solar spectrum ( 1.5 eV) •Good transport properties • Full absorption within absorber’s thickness
Need for asymmetry
Basic Solar Cell Concept
![Page 10: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/10.jpg)
p-n junction: cell asymmetry
Energ
iy
Conduction band
Valence band
Spatial coordinate
p
n
p n
E
![Page 11: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/11.jpg)
p-n junction
![Page 12: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/12.jpg)
Physics of p-n junction PV devices
– Electronic structure of solids
– Doping
– Optical absorption – generation
– Recombination
– Transport
– Limits of PV conversion
– p-n junction
– p-n junction as a PV device
– Efficiency of a PV device
![Page 13: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/13.jpg)
Fundamental equations of transport
Current density
Maxwell (Poisson)
Continuity equation
Diffusion equations for minority carriers
![Page 14: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/14.jpg)
IV characteristics and equivalent circuit
L
kTqV IeII )1( /
0
![Page 15: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/15.jpg)
Figures of merit
•Corrente di corto circuito Isc, efficienza quantica QE, risposta spettrale SR
•Tensione di circuito aperto
•Rendimento
LSC IQEI )()(
QEhc
qSR
1ln
0I
I
q
kTV L
OC
•Fill Factor OCSC
MPMP
VI
VIFF
![Page 16: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/16.jpg)
Solar cell efficiency
![Page 17: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/17.jpg)
Thermodynamic limits
%951 S
ACarnot
T
T TA : cell temperature at room temperature
TS : temperature of Sun Carnot Limit
Landsberg Limit 93.3% (86.8%, series of black bodies as converter)
Schokley – Queisser (SQ) Limit: Converter is one single semiconductor
![Page 18: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/18.jpg)
En
erg
y
Conduction Band
Valence Band
+ -
Thermodynamic limits
![Page 19: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/19.jpg)
Electric losses
Rs: Resistenza di serie
Rp: Resistenza di shunt (parallela)
![Page 20: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/20.jpg)
Losses
• Termalizzazione di fotoni energetici
• Perdite alla giunzione • Resistenze parassite • Perdite ai contatti
• Ricombinazione (radiativa, SRH, Auger, superficie)
• Ombreggiamento dei contatti • Riflessione
• Trasmissione (mancato assorbimento)
• Trasporto
![Page 21: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/21.jpg)
Where are we?
Green et al.: Solar Cell Efficiency Tables (Version 53), Progress in PV: Research and Applications 2018
![Page 22: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/22.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 23: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/23.jpg)
Photovoltaic technologies:
state of the art
1. Commercial technologies
![Page 24: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/24.jpg)
Effic
iency
Time
30% (single junction limit)
Silicon
2019
26.1%
Technical evolution and growth potential
![Page 25: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/25.jpg)
Crystalline silicon modules
Average Commercial Module Efficiency
![Page 26: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/26.jpg)
100
80
60
40
20
Effic
ien
cy (
%)
Cost ($/m2)
100 0 200 300 400 500
3.5 $/W
1 $/W
0.5 $/W 0.2 $/W 0.1 $/W
Economical
convenience
SQ limit for single junction
Grid parity
Ultimate thermodynamic
limit
Silicon
technology
Crystalline silicon modules - Techno-economic positioning -
![Page 27: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/27.jpg)
JA Solar, inc.
New silicon-based commercial technologies: «Black» silicon
€/kWh reduction driver: higher efficiency at constant cost
![Page 28: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/28.jpg)
bSolar, inc.
€/kWh reduction driver: higher collection area at constant cost
New silicon-based commercial technologies:
Bifacial technology
![Page 29: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/29.jpg)
Canadian Solar, inc.
Standard module Module based on MWT
Both electrical contacts in the back
€/kWh reduction driver: lower manufacturing cost at constant efficiency
New silicon-based commercial technologies:
MWT Metal Wrap-Through
![Page 30: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/30.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 31: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/31.jpg)
Effic
iency
Time
30% (single junction limit)
Silicon
2019
26.1%
Technical evolution and growth potential
![Page 32: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/32.jpg)
Silicon use: 1.5 – 3 kgSi/kWp www.pvcdrom.pveducation.org
2
00
m
Downsides of Si-based modules
![Page 33: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/33.jpg)
Energy cost is high!
Silicon costs money and energy
Incidence of silicon cost on the module energy
and monetary cost: > 50%
![Page 34: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/34.jpg)
g
dN
dNd
df
ph
ph
0
0
)(
)())(exp(1(
)(
Frac
tio
n o
f U
sefu
l Ph
oto
ns
Ab
sorb
ed
Thickness [m]
Thin film technology - Based on materials with better light absorption properties-
![Page 35: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/35.jpg)
Thin film technology:
CIGS, a-SI, CdTe
1 - 8 µm
CIGS: • Solar Frontier, inc. • Solibro, GmbH • Miasolé, ltd. • ... (several global companies)…
CdTe: • First Solar, inc.
a-Si • Sharp, inc. • Sunerg, srl
![Page 36: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/36.jpg)
Thin film technology: aesthetics, building integration, reduction of installation cost
![Page 37: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/37.jpg)
Thin film technology: CIGS, a-SI, CdTe - cost comparison with silicon-based modules -
![Page 38: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/38.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 39: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/39.jpg)
Effic
iency
Time
30% (single junction limit)
Silicon Thin film
2019
26.1%
23.3%
Technical evolution and growth potential
![Page 40: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/40.jpg)
100
80
60
40
20
Effic
ien
cy (
%)
Cost ($/m2)
100 0 200 300 400 500
3.5 $/W
1 $/W
0.5 $/W 0.2 $/W 0.1 $/W
Economical
convenience
SQ limit for single junction
Grid parity
Ultimate thermodynamic
limit
Silicon
technology Thin film
tech.
Thin film PV modules - Techno-economic positioning -
![Page 41: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/41.jpg)
Impact of Thin Film Technology is Dropping
![Page 42: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/42.jpg)
1.
Absorption
of solar radiation
Generation
of electrical charges
2.
Extraction
of electrical charges
Electrical energy
En
erg
y
+ -
Basic working principle of a PV cell - an electron’s perspective -
![Page 43: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/43.jpg)
Multijunction («tandem») cells - A more efficient use of the solar radiation -
![Page 44: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/44.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 45: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/45.jpg)
100
80
60
40
20
Effic
ien
cy (
%)
Cost ($/m2)
100 0 200 300 400 500
3.5 $/W
1 $/W
0.5 $/W 0.2 $/W 0.1 $/W
Economical
convenience
SQ limit for single junction
Grid parity
Ultimate thermodynamic
limit
Silicon
technology Thin film
tech.
Multijunction cells - Techno-economic positioning -
Multijunction
![Page 46: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/46.jpg)
Photovoltaic technologies:
state of the art
2. Frontier technologies
![Page 47: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/47.jpg)
Dye Sensitized Solar Cell - DSSC
![Page 48: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/48.jpg)
Dye Sensitized Solar Cell (DSSC)
Graetzel Cell
![Page 49: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/49.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 50: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/50.jpg)
Organic photovoltaics - OPV
![Page 51: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/51.jpg)
Why Organic Cells?
•Low cost •High thoughput production •Flexibility
![Page 52: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/52.jpg)
Voc = (LUMOA – HOMOD) – 0.3 eV
h+
e- e-
h+
Voc
ELECTRON DONOR ELECTRON ACCEPTOR
HOMO
LUMO
HOMO
LUMO
Physics of Organic Solar Cells
Ener
gy
![Page 53: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/53.jpg)
Bulk Heterojunction Solar Cells
+ -
P3HT (electron donor)
PCBM (electron acceptor)
![Page 54: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/54.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 55: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/55.jpg)
100
80
60
40
20
Effic
ien
cy (
%)
Cost ($/m2)
100 0 200 300 400 500
3.5 $/W
1 $/W
0.5 $/W 0.2 $/W 0.1 $/W
Economical
convenience
SQ limit for single junction
Grid parity
Ultimate thermodynamic
limit
Silicon
technology Thin film
tech.
DSSC e OPV - Techno-economic positioning -
Multijunction
OPV
DSSC
![Page 56: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/56.jpg)
Photovoltaic technologies:
state of the art
3. Beyond the frontier -
nanotechnology
![Page 57: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/57.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 58: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/58.jpg)
Effic
iency
Time
30% (single junction limit)
Silicon Thin
film
2019
26.1%
23%
47% (new generation)
Enhancement potential
New generation
![Page 59: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/59.jpg)
Nanotechnology and PV: Why?
• Morphologic advantages: nanometric
structures have a lot of surface area
(e.g. DSSC)
• The optoelectronic properties of materials are
dominated by phenomena occurring at the
nanoscale we need to engineer the
nanostructure of materials
• Nanoscale phenomena are governed by
quantum mechanics nanomaterials can
exploit untapped physics at the macroscale
(e.g. intermediate band)
![Page 60: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/60.jpg)
En
erg
y
+ -
Thermalization of electrons: wasted energy!
![Page 61: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/61.jpg)
Wasted energy!
Exploiting high-energy
photons
Limiting efficiency: 45% (86.6% under concentration)
Nanotech and Photovoltaics: - Better use of high-energy photons: MEG (Multiple Exciton Generation) -
Special nanoparticles (quantum dots) favor the generation of more than one electron per photon
![Page 62: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/62.jpg)
En
erg
y
+ -
Low energy photons are lost
![Page 63: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/63.jpg)
Beyond the single junction limit
- Intermediate Band Materials: Using Low Energy Phonons-
0
500
1000
1500
2000
2500
0 500 1000 1500 2000
W m
2 n
m-1
Wavelength [nm]
![Page 64: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/64.jpg)
Conduction Band Valence Band
Intermediate
Band
Making an Intermediate Band Material
Quantum dots embedded in a semiconductor
![Page 65: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/65.jpg)
Assemblying Quantum Dots into Colloidal Solid Films
![Page 66: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/66.jpg)
From a Colloidal Solid to a Dense Nanostructured Film
core
shell
Thermal Treatment
Use Core/Shell Nanocrystals
![Page 67: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/67.jpg)
Nanotech and Photovoltaics: - Exploiting low-energy photons: Intermediate Electronic Band-
![Page 68: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/68.jpg)
The latest frontier Perowskite-based solar cells
• Most promising thin film technology (high efficiency) • Cheap, high-throughput manufacturing
![Page 69: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/69.jpg)
The latest frontier Perowskite-based solar cells
![Page 70: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/70.jpg)
multijunction
crystalline silicon
thin films
emerging technologies
![Page 71: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/71.jpg)
Effic
iency
Time
30% (single junction limit)
Silicon Thin
film
2019
26.1%
23%
47% (new generation)
Enhancement potential
New generation
![Page 72: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/72.jpg)
100
80
60
40
20
Effic
ien
cy (
%)
Cost ($/m2)
100 0 200 300 400 500
3.5 $/W
1 $/W
0.5 $/W 0.2 $/W 0.1 $/W
Economical
convenience
SQ limit for single junction
Grid parity
Ultimate thermodynamic
limit
Silicon
technology Thin film
tech.
Next-generation solar cells - Techno-economic positioning -
Multijunction
OPV
DSSC
![Page 73: Summer School on Energy Giacomo Ciamician...- an electron’s perspective - Multijunction («tandem») cells - A more efficient use of the solar radiation - ... state of the art 3.](https://reader033.fdocuments.in/reader033/viewer/2022042909/5f3c25819451165f12066355/html5/thumbnails/73.jpg)
Concluding Remarks
• The cost reduction of the PV-kWh enabled attainment of grid parity in many Countries
• Most of the cost reduction has been driven by the economies of scale
• Nevertheless, technological innovation and breakthroughs are still important
• Current technologies have shown incremental, marginal improvements
• «Emerging» technologies such as Organic PV and DSSC need to prove robustness. They will hardly play a role in power generation
• The newest technologies (perovskites, quantum dot-based) have the chance to be a real breakthrough by combining high efficiency and extremely low cost