Gaussian traps, shallow

We treat here the case of shallow Gaussian traps. The equations reduce to those applicable to single level traps by making the standard deviation at = 0. If the Poole-Frenkel effect (PEE) is included the J-V relation for a device containing shallow traps is given... 

If we consider a sample with shallow Gaussian traps and include PEE, the sample behaves as if there are no traps and the mobility is field dependent given by Eq. (3.56) far as the dependence of J on V is concerned. The zero field mobility and its temperature dependence are different in the two equations. If the traps are at a single energy level, <7t = 0 and the temperature variation of the mobility also becomes the same in the two cases. Eq. (3.58) represents both the models, it reduces to the existing shallow trap model (without PEE) when = 0 and to the existing field dependent mobility model when 6 = exp(-EtfkT). 

Fig. 16. Density of states showing five Gaussian trap levels, each with total integrated density 1 X 10 cm , plus shallow donor level corresponding to a net donor concentration ofS X 10 cm . The position ofthe bulk Fermi energy is taken to be 50 meV below and the gap energy is assumed to be 1.8 eV.

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