Effect of Irradiation on Nanoisland Formation and Structural Evolution of Bi₂Te₃ Thermoelectric Materials

Thermoelectric materials, particularly those derived from Bi2Te3, have received significant interest because of their capacity to directly transform thermal energy into electrical power, thereby making them suitable for energy conversion applications. This research centered on the surface morphology of Bi2Te3 crystals, specifically examining the (0001) surfaces both prior to and following irradiation, employing Atomic Force Microscopy (AFM) for analysis. The formation of nanoislands and their fractal nature were studied, which helped to understand their nucleation and growth through Ostwald ripening (OS), a process where smaller islands combine to form larger ones. This research also examined radiation affecting the structure and thermoelectric properties of materials made from Bi₂Te₃. The fractal characteristics of these nanostructures lead to the appearance of nanoislands of different sizes. The present investigation centered on the fractal characteristics inherent in nano-objects, thereby facilitating the emergence of multi-scale nanoislands. This research investigated the fractal features of nano-objects, which are instrumental in the generation of nanoislands across a spectrum of length scales. Consequently, the fractal morphology exhibited by nanoscale formations gives rise to nanoislands that encompass diverse size regimes.