INFLUENCE OF THE MEYER-NELDEL RULE ON CHARGE DEEP LEVEL TRANSIENT SPECTRA
Peter Kluvánek - Drahoslav Barančok - Vojtech Nádaždy
energy levels is investigated. We performed computer simulations of QDLTS spectra for a box-shaped energy distribution
considering MNR via energy dependence of the exponential prefactor t0 of the charge emission rate defined by
The main feature of these simulations is that below the critical temperature T0=E0/k
the QDLTS spectra do not become broader with increasing the rate window as those observed for the distribution G(E) with
energy independent t0. To justify the viability of this description, we measured the continuum of interface states of
two MOS structures prepared on crystalline silicon (c-Si) and undoped hydrogenated amorphous silicon (a-Si:H) substrates.
Performed simulations were related to QDLTS spectra measured with large-pulse excitation which give a response from a wide
energy interval. Unlike the former sample, QDLTS spectra of a-Si:H sample did not broaden with increasing the rate window.
Their behaviour can be interpreted by MNR underlain in the prefactor t0 providing support for our consideration.
Using a small-signal QDLTS method, which measures a limited fraction of the interface state continuum, the dependence of
t0 on the activation energy E was constructed for both samples. It yielded the energy independent
t0 and MN
energy E0=0.38eV for interface states measured on c-Si and a-Si:H samples, respectively.
Keywords: Meyer-Neldel rule, undoped hydrogenated amorphous silicon, charge deep-level transient spectroscopy, crystalline