Does Quantum Efficiency of solar cells also depend on crystal structure of light absorbing layer of PV device ?
Dear Chandra,
welcome,
The crystal structure of the absorbing layer can have its effect on the electrical and the optical properties of such layers. Think on the solar cells made from single crystal silicon, poly crystalline silicon and amorphous silicon.
It is so that the presence of the grain boundaries reduces the mobility of charge carriers and also the defects at the grain boundaries act as effective recombination centers reducing the minority carrier lifetime.
Also, as the grains get more fine its bandgap increases and its band structure changes. This leads to change of its absorption behavior of the material. As demonstration to see the effect of crystal structure on the performance of the materials one can compare single crystal silicon and amorphous silicon. Single crystal silicon has band gap of 1.1eV while amorphous silicon has a bandgap of about 1.7 eV. About one micrometer is sufficient to absorb the incident solar radiation while single crytal silicon needs about 300 um to absorb the incident solar radiation.
But the highest quality materials are crystalline from the point of view of conduction.
Best wishes
Yes it depends. Internal crystal structure decides in which part of the solar spectrum it will respond.
Dear Chandra,
welcome,
The crystal structure of the absorbing layer can have its effect on the electrical and the optical properties of such layers. Think on the solar cells made from single crystal silicon, poly crystalline silicon and amorphous silicon.
It is so that the presence of the grain boundaries reduces the mobility of charge carriers and also the defects at the grain boundaries act as effective recombination centers reducing the minority carrier lifetime.
Also, as the grains get more fine its bandgap increases and its band structure changes. This leads to change of its absorption behavior of the material. As demonstration to see the effect of crystal structure on the performance of the materials one can compare single crystal silicon and amorphous silicon. Single crystal silicon has band gap of 1.1eV while amorphous silicon has a bandgap of about 1.7 eV. About one micrometer is sufficient to absorb the incident solar radiation while single crytal silicon needs about 300 um to absorb the incident solar radiation.
But the highest quality materials are crystalline from the point of view of conduction.
Best wishes
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