what is the range of temperature there?
It is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law.
Photosphere
The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. 
what is the name of the suns surface layer Photosphere
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Photosphere [SEP] Temperature
The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface.