A high electron mobility transistor (HEMT) controls large currents by applying a small voltage to a thin sheet of electrons. The density and mobility of the electrons in the sheet are critical for the operation of the HEMT. HEMTS consisting of AlGaN/GaN/Si are being studied because they promise better performance at higher powers, temperatures, and frequencies than conventional silicon HEMTS can achieve. In one study, the Hall effect was used to measure the density of electrons in one of these new HEMTS. When a current of 12.1 ?A flows through the length of the electron sheet, which is 1.12 mm long, 0.223 mm wide, and 15.1 nm thick, a magnetic field of 1.05 T perpendicular to the sheet produces a voltage of 0.511 mV across the width of the sheet. What is the density of electrons per m3 in the sheet?

A high electron mobility transistor (HEMT) controls large currents by applying a small voltage to a thin sheet of electrons. The density and mobility of the electrons in the sheet are critical for the operation of the HEMT. HEMTS consisting of AlGaN/GaN/Si are being studied because they promise better performance at higher powers, temperatures, and frequencies than conventional silicon HEMTS can achieve. In one study, the Hall effect was used to measure the density of electrons in one of these new HEMTS. When a current of 12.1 ?A flows through the length of the electron sheet, which is 1.12 mm long, 0.223 mm wide, and 15.1 nm thick, a magnetic field of 1.05 T perpendicular to the sheet produces a voltage of 0.511 mV across the width of the sheet. What is the density of electrons per m3 in the sheet?