The Temperature Dependence of the Spin Resonance in Boron Doped a‐Si:H

The temperature dependence of the g = 2.01 ESR line in boron doped a‐Si has recently been studied by the Marburg group. For this line the g‐value, linewidth, and lineshape factor depend both on temperature and doping level. The temperature shift of the g‐value is explained by a model in which the g‐factor depends explicitely on energy and the temperature dependence is a result of the temperature shift of the mean energy of the spins. This model is combined with a density of states distribution recently reported to interpret the de transport data. From this the energy dependence of the g‐factor is obtained and the linewidth ΔH due to g‐value broadening as a function of temperature and doping level is calculated. At elevated temperatures an additional contribution to the linewidth, δHpp(T), is observed and is interpreted by the Marburg group as due to spin relaxation via exchange interaction between the localized spins and rapidly relaxing carriers in extended states. It is shown that long‐ranged potential fluctuations combined with this relaxation mechanism can easily explain both the relation between the dc conductivity σ and δHpp(T) and the rapid rise of the lineshape factor l as δHpp(T) begins to dominate the total linewidth.