Interface and Bulk Properties of High-<i>K</i> Gadolinium and Neodymium Oxides on Silicon

Abstract

The paper presents the results of electrical characterization of the interface and bulk properties of high-k Gd2O3 and Nd2O3 dielectrics epitaxially grown on silicon substrates. The limitations of the conductance technique for correct determination of the interface state density due to the presence of leakage currents through the dielectric are discussed. The charge carrier transport through the dielectric film was found to occur via the variable-range hopping conductance mechanism. The density of the interface states and their energy distribution for (100) and (111) Si orientation and the Gd2O3/Si and Nd2O3/Si interfaces were determined. The density and energy location of the bulk localized states in the band gap of the Gd2O3 and Nd2O3 dielectrics were estimated and a plausible nature of the observed defects was suggested.

Charge Carrier Transport, Trapping, and Recombination in PEDOT:PSS/n-Si Solar Cells

“…The presence of such centers in the Au/PEDOT:PSS/n-Si sample can be explained by the appearance of a thin interfacial SiO x layer between PEDOT:PSS and silicon due to native oxidation of silicon during the SC production. P b centers were also detected in samples with high- k dielectric (Gd 2 O 3 and Nd 2 O 3 ) layers on silicon . As for the Au/PEDOT:PSS/n-Si junction, the determined activation energy of 0.31 eV corresponds to the contribution of E v + 0.3 eV hole traps to the admittance signal, nearest to the Fermi level, which leads to the observation of the G /ω peak at low modulation frequencies.…”