21-07-2014, 12:49 PM
organic solar cell
[attachment=66062]
INTRODUCTION
Organic solar cell is a polymer solar cell that uses organic electronics for light absorption and charge transport to produce electricity from sunlight by photovoltaic effect.
The small molecules and polymers used to make Organic solar cell have large conjugated system.
Photon absorbtion creates an excited state i.e. excitons
TYPES OF ORGANIC SOLAR CELL[/b]
The types of OSC are:-
Single layer Organic solar cell
Bilayer Organic solar cell
Bulk heterojunction Organic solar cell
Graded heterojunction Organic solar cell
BILAYER ORGANIC SOLAR CELL
Two different layers sandwiched between metallic conductor.
Two layers of material have difference in electron affinity and ionisation energy.
Layer with high electron affinity is electron acceptor and other layer is electron donor
Due to large thickness of junction than diffusion length of excitons, efficiency is low
BULK HETeROJUNCTION OSC
Electron acceptor and donor mixed together, forming polymer blend.
Length of polymer blend is same as exciton diffusion length.
Efficiency is improved.
Heterojunction mainly consists of conductive polymers and fullerenes
graded heterojunction osc
Electron acceptor and electron donor are mixed together like in bulk heterojunction but the gradient is gradual.
This architecture combines the short electron travel distance with the advantage of charge gradient in bilayer technology which improves the efficiency
Working of organic solar cell
The difference of work function between the two conductors sets up an electric field in the organic layer. When the organic layer absorbs light, electrons will be excited to the LUMO and leave holes in the HOMO, thereby forming excitons.
The potential created by the different work functions helps to separate the exciton pairs, pulling electrons to the positive electrode and holes to the negative electrode. The current and voltage resulting from this process can be used to do work
Future aspects of organic solar cell
Development of environment friendly devices
Another possibility would be to combine solar cells, sensors and electronic circuits on a small strip of plastic to form a self-sufficient power Microsystems
organic photovoltaic materials that can be made or processed in liquid form, allowing them to be applied to a wide array of surfaces
Light weight and flexible organic solar cells can be printed over cloths
conclusion
Organic cell offer to provide an eco-friendly, large area flexible solar cell technology at low production cost.
There is always a trade-off between cost and efficiency , OSC have low efficiency but are cost effective . So, OSC’s are more economic to use .
They are the cheaper alternative of inorganic solar cell and in future main focus will be on increasing its efficiency and operating stability.
Although it faces the limitations like low efficiency, stability problem etc. but still It has the potential to be a part of world’s solution to the future of energy.
[attachment=66062]
INTRODUCTION
Organic solar cell is a polymer solar cell that uses organic electronics for light absorption and charge transport to produce electricity from sunlight by photovoltaic effect.
The small molecules and polymers used to make Organic solar cell have large conjugated system.
Photon absorbtion creates an excited state i.e. excitons
TYPES OF ORGANIC SOLAR CELL[/b]
The types of OSC are:-
Single layer Organic solar cell
Bilayer Organic solar cell
Bulk heterojunction Organic solar cell
Graded heterojunction Organic solar cell
BILAYER ORGANIC SOLAR CELL
Two different layers sandwiched between metallic conductor.
Two layers of material have difference in electron affinity and ionisation energy.
Layer with high electron affinity is electron acceptor and other layer is electron donor
Due to large thickness of junction than diffusion length of excitons, efficiency is low
BULK HETeROJUNCTION OSC
Electron acceptor and donor mixed together, forming polymer blend.
Length of polymer blend is same as exciton diffusion length.
Efficiency is improved.
Heterojunction mainly consists of conductive polymers and fullerenes
graded heterojunction osc
Electron acceptor and electron donor are mixed together like in bulk heterojunction but the gradient is gradual.
This architecture combines the short electron travel distance with the advantage of charge gradient in bilayer technology which improves the efficiency
Working of organic solar cell
The difference of work function between the two conductors sets up an electric field in the organic layer. When the organic layer absorbs light, electrons will be excited to the LUMO and leave holes in the HOMO, thereby forming excitons.
The potential created by the different work functions helps to separate the exciton pairs, pulling electrons to the positive electrode and holes to the negative electrode. The current and voltage resulting from this process can be used to do work
Future aspects of organic solar cell
Development of environment friendly devices
Another possibility would be to combine solar cells, sensors and electronic circuits on a small strip of plastic to form a self-sufficient power Microsystems
organic photovoltaic materials that can be made or processed in liquid form, allowing them to be applied to a wide array of surfaces
Light weight and flexible organic solar cells can be printed over cloths
conclusion
Organic cell offer to provide an eco-friendly, large area flexible solar cell technology at low production cost.
There is always a trade-off between cost and efficiency , OSC have low efficiency but are cost effective . So, OSC’s are more economic to use .
They are the cheaper alternative of inorganic solar cell and in future main focus will be on increasing its efficiency and operating stability.
Although it faces the limitations like low efficiency, stability problem etc. but still It has the potential to be a part of world’s solution to the future of energy.