Are pyroelectricity and the peltier-seebeck effect the same thing?
They are close, but not really the same. While both rely on a temperature differential to create a potential differential in a substance, Pyroelectricity deals with a single substance. Seebeck and Peltier showed that with two dissimilar metals, a temperature difference at the junction of the metals produced a voltage (Seebeck) and vice versa (Peltier).
Those links are great, but if you want short and sweet :
Seebeck effect : V is a function of dT/dx, and happens in regular conductors.
Pyroelectricity : V is a function of dT/dt, and only happens with certain ionic crystals.
Separate names with a comma.