Thermoelectric and galvanomagnetic investigations of VI group semiconductors Se and Te at high pressure up to 30 GPa

At ultrahigh pressures up to 30 GPa the thermomagnetic Nernst–Ettingshausen effect was measured for Te and Se samples in the vicinity of semiconductor–metal phase boundary. The significant longitudinal and transverse Nernst–Ettingshausen effects observed for both semiconductors allowed one to estimate the scattering parameter for charge carriers. The increase in hole mobility obtained from longitudinal and transverse Nernst–Ettingshausen effects being consistent with the growth of magnetoresistance under pressure gave confirmation to the decrease in the effective mass of holes at the closure of direct semiconductor gap.