Hall coefficient and resistivity were measured as functions of temperature on uncompensated indium arsenide specimens. A room temperature mobility of 30 000 ${\mathrm{cm}}^2$/volt sec was obtained for a donor concentration of 1.7×${10}^{16}$ atoms/${\mathrm{cm}}^3$. For this impurity density, no indication of a separation of the donor level from the conduction band was observed.

• Received 4 September 1956

DOI:https://doi.org/10.1103/PhysRev.104.1562