Measurement of drift velocity of electrons in silicon by exciting a diode structure with short superradiant laser pulses

The drift velocity of electrons in high-resistivity silicon was measured by studying the current pulses induced in a surface barrier diode by subnanosecond light pulses from a super-radiant gas laser. Measurements were made for electric field strengths up to ≃1.2 × 10⁴V/cm, at room temperature. The low-field mobility value obtained was 1400 ±5O cm²/V.s. The decrease of mobility for higher fields is in substantial agreement with previous results though the nonlinearity at high field is somewhat smaller than that found in other time of flight measurements. Analytical expressions that approximate the experimental trend of mobility versus field are briefly discussed.