Measurements of Carrier Confinement at β-FeSi2-Si Heterojunction by Electroluminescence

Abstract: A Si p-π-n diode with β-FeSi2 particles embedded in the unintentionally doped Si (p-type) was designed for determining the band offset at β-FeSi2-Si heterojunction.When the diode is under forward bias,the electrons injected via the Si np- junction diffuse to and are confined in the β-FeSi2 particles due to the band offset.The storage charge at theβ-FeSi2-Si heterojunction inversely hamper the further diffusion of electrons,giving rise to the localization of electrons in the p-Si near the Si junction,which prevents them from nonradiative recombination channels.This results in electroluminescence (EL) intensity from both Si and β-FeSi2 quenching slowly up to room temperature.The temperature dependent ratio of EL intensity of β-FeSi2 to Si indicates the loss of electron confinement following thermal excitation model.The conduction band offset between Si and β-FeSi2 is determined to be about 0.2eV.


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