In the component point of view it can be explained by the electron mobility versus the role mobility. The electron mobility is 1400 cm2/ (V·s) and the hole mobility is around 450 cm2/ (V·s) so the n-type based component is faster than p-type. There are also some mechanical issues due to the doping atom size.
In photovoltaic point of view, the n-type Si has no light induced degradation effect and it shows high carrier lifetime. Whereas, the p-type (boron doped ) Si strongly degrades under illuminations. Moreover, the n-type Si is highly tolerable to harmful impurities like iron in Si. Thus, the n-type Si is better than p-type Si for solar cells with high and stable efficiency.
Si (group14 element with 4valence electrons)) can form four bonds with four more Si atoms. p- type Si semiconductor(SMC) is formed when a group 13 element(B.Al.Ga,In) called dopant having only 3 valence electrons is added as impurity as follows:
This electron deficient dopant forms three bonds with each one of the three Si and leaves ONE BOND UNSATISFIEDor a hole is created which otherwise would have contained one electron.In a way, this hole being empty is analogous to positive hole . With the presence of a definite mole % of the dopant, a large number of such holes are created in the otherwese non conducting Si crystal. When potential differenc is applied, such holes can move across the crystal and can conduct electricity to some extent. As the electricity is conducted by the movement of these POSITIVE HOLES,hence such SMC are called p-type SMC.
n- type Si (SMC) is formed when a group 15 element dopant(P.As.Sb) having 5 valence electrons is added as impurity as follows:
These electron rich dopants form four bonds with each one of the four Si and leave one electron FREE. With the presence of a definite mole % of the dopant, a large number of such free electrons now become available in the otherwese non conducting Si crystal. When potential differenc is applied, such free electrons can move across the crystal and can conduct electricity in the NORMAL way, i.e., as happens in metals where free electrons are the conductors. As the electricity is conducted by the movement of the electrons (in the normal way), hence such SMC are called n-type SMC.
As in n-type Si SMC, the electricity is conducted the smallest free nonrestrive electrons while in p-type Si SMC, it is conducted the movements of finite sized positive holes whose free movement can be restricted by the neighbouring Si /dopant species, p- tpye Si SMC are expected to be inferior
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