Abstract
This work has developed a hybrid organic/inorganic heterostructure based on BGaAs/GaAs epilayer capped with Poly (3-hexylthiophene) (P3HT) using the spin-coating method. The proposed heterostructure is investigated experimentally and theoretically. The successful growth has been illustrated structurally using High-Resolution x-ray Diffraction. The optical properties of hybrid P3HT/BGaAs/GaAs are identified through steady-state photoluminescence. The works focus on the effect of the capping layer on the localization phenomenon induced by the inhomogeneity in the BGaAs alloy and the polymer layer. A broadening in the emission properties over the infrared and visible range of light is detected at low and room temperatures. An electrons transfer process P3HT to BGaAs epilayer has occurred referring to the quenching of the photoluminescence intensity of P3HT. As a function of temperature, the change of the emission features was observed and is explained using a thermally activated redistribution model within a Gaussian distribution of localized states. Different parameters have been derived for the hybrid heterostructure such as the Huang-Rhys factor (S), the carrier recombination time (tau(r)), and the broadening parameter of the Gaussian distribution for localized states (sigma). We show that the proposed P3HT cap layer could replace the conventional GaAs cap layer for photovoltaic devices.