The most common form of solar cells are based on the photovoltaic (PV) effect
Two layer semi-conductor device produces a photovoltage or potential difference between the layers
No fuel cost or fuel supply problem
No pollution
High reliability
Small amount of power required
Depend on place and climate
Large scale:
Ocean navigation aid
Telecommunication system
Remote moni
▶find photoelectric effect
Heinrich R. Hertz
▶design solar cell experiment
Cell (Basic cell of the solar cell)
↓
Module (Form of assembling Cells)
↓
Array (Solar panel)
Hole moves toward
P type semiconductor
Electron moves toward
N type semiconductor
↓
Electrode formed
Current flows
↓
Solar cell generate
plastic film type solar cell
Prospect : Due to th
Converts sunlight directly into electricity
Non polluting
Long lasting sources of energy
No need of maintenance
In the long run, solar electricity is cheaper
Electrons of dye absorb solar energy
Electrons of dye are excited & Generate electron-hole pairs
Electrons transfer from dye to FTO via TiO2
1/2 I3- + e 3/2 I- at counter electrode
3/2 I- 1/2
Single junction structure
Poor efficiency(<30%)
Conversion rate ~ # of photon
Multi-layer structure
high efficiency(2times of 1st type)
Conversion rate ~ # of photon
Use photon energy
Very high(1hv → 2e)
Theoretical level
Dye electrons are excited by solar energy absorption
They are injected into the conduction band of TiO2
Get to counter-electrode (cathode) through the exter