How thermal properties / parameters of as synthesized semiconductor nanoparticles can be alter as a function of its synthesis temperature as well as doping level of copper concentration in doped SnSe. Thermal properties is studied when materials dimensions are reduces to few nanometer is also explained with the help of theoretical physics. Such types of mathematical theoretical model were exists but experimental data rarely reported or performed at nano level scale particularly for thermal characterization. Energy of activation for pure and copper doped SnSe semiconducting nanoparticles is explained with the help of mathematics and concepts of physics behind that mathematics. How and why size of nanoparticles as well as doping level of Copper concentration plays important role in altering the thermal properties of material is also discussed in depth.