An assessment on crystallization phenomena of Si in Al/a-Si thin films via thermal annealing and ion irradiation

Abstract

In the present study, crystallization of amorphous-Si (a-Si) in Al/a-Si bilayer thin films under thermal annealing and ion irradiation has been investigated for future solar energy materials applications.

Micro‐morphological investigations on wettability of Al‐incorporated c‐Si thin films using statistical surface roughness parameters

“…The ion irradiation on c‐Al/ a ‐Si films resulted the crystallization of Si in bilayer films, and the top unreacted Al layer were chemically etched off by wet selective etching. The crystallization of Si in c‐Al/a‐Si system under ion irradiation at temperature 100°C and the formation of Al‐incorporated c‐ Si or homogeneous c ‐Si thin film (i.e., absorber layer) were confirmed by transmission electron microscopy (TEM) and electron‐dispersive x‐ray (EDX) analysis, which are discussed in our previous work 28–30 . The crystallization process can be discussed via diffusion mechanism.…”

“…The crystallization process can be discussed via diffusion mechanism. During ion irradiation, the Si atoms diffused along the grain boundary of the, Al layer and after a sufficient accumulation of Si atoms at the grain boundary, the nucleation started and growth occurred 28–30 . In the following sections, we are presenting a new level of topographical understanding and wettability property of the absorber surfaces with the help of 3D surface topography, statistical parameters analysis, and contact angle measurements.…”

“…In order to prepare c‐Al/ a ‐Si interface, 50‐nm thin Al films were deposited on the top of a ‐Si films using thermal evaporation without breaking the vacuum. The as‐prepared Al (50 nm)/ a ‐Si (150 nm) bilayer films were then irradiated at a temperature of 100°C by 100 ‐MeV Ni +7 ions with different fluences of 1 × 10 12 ions‐cm −2 , 5 × 10 12 ions‐cm −2 , 1 × 10 13 ions‐cm −2 , and 5 × 10 13 ions‐cm −2 using 15 UD Pelletron accelerator facility of Inter University Accelerator Center (IUAC), New Delhi, after estimating the range of ions by Stopping and Range of Ions in Matter (SRIM) simulation code 28–31 . The ion irradiation resulted the crystallization of Si in bilayer films and the top unreacted Al layer were chemically etched off by wet selective etching using “Aluminum Etchant‐Type A” (Sigma‐Aldrich) solution.…”

“…In order to obtain this absorber layer, the as‐prepared c ‐Al (50 nm)/ a ‐Si (150 nm) (i.e., pristine) thin films are irradiated at a temperature of 100°C using 100‐MeV Ni +7 ions with the fluences of 1 × 10 12 ions‐cm −2 , 5 × 10 12 ions‐cm −2 , 1 × 10 13 ions‐cm −2 , and 5 × 10 13 ions‐cm −2 . The ion irradiation on c ‐Al (50 nm)/ a ‐Si (150 nm) leads to the crystallization of Si in bilayer film 28–30 . In order to expose the absorber layer, remaining Al from the top layer of the bilayer samples is selectively etched‐off.…”

Perspectives on metal induced crystallization of a-Si and a-Ge thin films

“…This model has been widely used to describe the track formation, defect annealing, recrystallization in semiconductors and metal modications etc. [150][151][152][153][154][155][156][157]…”