Modeling the emission red-shift in amorphous semiconductors and in organic-inorganic hybrids using extended multiple trapping

A model of thermal relaxation within localized states based on the extended multiple trapping framework is used to describe the red-shift of the emission maximum intensity as the excitation energy decreases. The model is applied to amorphous hydrogenated silicon (a-Si:H) and to organic-inorganic hybrids systems giving values for the energy gap, E<Subscript>0</Subscript>, (1.896–3.882 eV) and for the β (4.36–12.08 eV<Superscript>-1</Superscript>) parameter that characterizes the experimental decay of the density of localized states within the gap consistent with those achieved by some other recombination models previously reported for a-Si:H.. The thermal relaxation within localized states model is more physically detailed incorporating radiative and non-radiative transition mechanism for carriers relaxing into localized states that are explicitly absent in the previously reported theoretical descriptions Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006