Dynamics of Carrier Generation by Photon Absorption in Semiconductor Gallium Arsenide

摘要

In this paper we focus on GaAs dynamics carrier generation by photon absorpstion as basic for the mechanism of optical sensor. This result will give the sensitivity and the ability of the semiconductor as an optical sensor. By analyzing the absorption coefficient as a function of photon energy, we can predict the created carriers (electrons and holes) which become an electrical current. The rate carrier generation per unit power in GaAs as a function of photon energy has been calculated and it is in the range of 1.2-5.0 eV. In a room temperature (300 K), the result below energy gap GaAS (1.4 eV) less than 8 x 10~3 cm~(-3)s~(-1)W~(-1). In the range of the energy gap (1.4 eV), the generation start to increase exponentially in the order of 10~5cm~(-3)s~(-1)W~(-1) and at photon energy of 5.0 eV will reach the peak in the order of 4 x10~5 cm~(-3)s~(-1)W~(-1).