Structural and Electrical Properties of Low-Energy Ion Beam Kr-Irradiated In/Se Bilayer

Anil K. Das; Aloke Verma; Vikram Singh; Arun K. Diwakar; Manju Bala; Devesh Kumar Avasthi; K. Asokan; S.K. Tripathi; Prabhakar Singh; S.A. Khan

doi:10.37591/jopc.v11i1.7038

Abstract

In the present work, In (~50 nm) over Se (~50 nm) thin films were deposited successively on an Si substrate by e-beam evaporation method under 2×10–5 mbar pressure. The In/Se bilayers were irradiated with low-energy ion beams of 350 keV Kr+1 with fluence of 3 × 1016 ions/cm2. The sample was subsequently characterized for phase formation using X-ray diffraction and thickness profile using Rutherford backscattering spectrometry analysis. In the pristine sample, X-ray diffraction exhibited phase formation, confirming mixing. Rutherford backscattering spectrometry also confirmed mixing of the two layers in the pristine sample. It also confirms that Se from second layer is mixed to the third layer of Si (substrate layer). This mixing is increased greatly by Kr ion irradiation. According to scanning electron microscopy analysis, stone-like nanostructures of various sizes have formed in the pristine sample. The surface is smoothened by the Kr ion irradiation. In addition, temperature-dependent electrical measurements of the pristine sample were made. The pristine sample showed n type charge carriers as predicted by Hall measurement. The resistivity of the pristine sample exhibited semiconductor behaviour as the temperature rises. The Kr-irradiated sample has very high resistance of the order of megaohms. So, Hall coefficient, Seebeck, and resistivity measurements could not be carried out.