07-08-2012, 03:56 PM
Solar Cell
[attachment=30430]
What is a Solar Cell?
A device that converts light energy (solar energy) directly to electricity.
The term solar cell is designated to capture energy from sunlight, whereas PV cell is referred to an unspecified light source.
It is like a battery because it supplies DC power.
Physics of Solar Cells
Semiconductor material can be p-type (hole carriers) or n-type (electron carriers)nductor
Built-In Electric Field
The charged atoms (ions) create an electric field.
This electric field makes it easy for current to flow in one direction, but hard to flow in the opposite direction.
Solar Cell Process Flow
Start with n-type silicon wafers
Cleaning the wafers
Sulfuric: peroxide - removes organics
Buffered Hydrofluoric acid - removes residual oxide
HCl: peroxide - removes heavy metals
Spin on dopant: a liquid source of boron (p-type impurity)
Anneal: 1000oC furnace step drives B into wafer (forming diode).
[attachment=30430]
What is a Solar Cell?
A device that converts light energy (solar energy) directly to electricity.
The term solar cell is designated to capture energy from sunlight, whereas PV cell is referred to an unspecified light source.
It is like a battery because it supplies DC power.
Physics of Solar Cells
Semiconductor material can be p-type (hole carriers) or n-type (electron carriers)nductor
Built-In Electric Field
The charged atoms (ions) create an electric field.
This electric field makes it easy for current to flow in one direction, but hard to flow in the opposite direction.
Solar Cell Process Flow
Start with n-type silicon wafers
Cleaning the wafers
Sulfuric: peroxide - removes organics
Buffered Hydrofluoric acid - removes residual oxide
HCl: peroxide - removes heavy metals
Spin on dopant: a liquid source of boron (p-type impurity)
Anneal: 1000oC furnace step drives B into wafer (forming diode).