Photoluminescence and photocurrent of Schottky diodes based on silicon nanocrystallites

Abstract

Photoluminescence (PL), Raman scattering and atomic force microscopy (AFM) investigations have been done for porous silicon (PSi) in as-prepared state. The Schottky barrier to porous silicon layer and ohmic electrical contact to p-type Si substrate have been created. Photocurrent spectral response and reverse current-voltage characteristics in the dark and with light exposition have been investigated for these structures. The photoelectric parameters of Schottky barrier have been discussed from the point of view of variation of the sizes of Si nanocrystallites.

Ballistic effect and optical properties of Si nanocrystallite structures

“…On the base of this measurement the effective mobility of hot electrons is estimated as 6000 cm 2 /Vs [10], which greatly exceeds normal electron mobility (1900 cm 2 /Vs) in Si and thus confirms the presence of hot carrier ballistic motion [10]. The effective ballistic transport regime realization in Si NCs (30-150 nm) can be the reason of photocurrent spectrum shift into the higher energy spectral range observed recently in PSi Schottky barriers with the NC size decreasing [11]. …”