Morphology Optimization of Bi₂Se₃ Thin Films for Enhanced Thermoelectric Performance

Abstract

Vapor–solid growth (VSG) is a cost-effective technique to synthesize Bi2Se3 materials with promising thermoelectric (TE) performance. In this work, smooth Bi2Se3 thin films with enhanced TE performance have been realized through regulating the carrier gas flow rate during the VSG process. The optimized morphology improves the electrical conductivity and decouples its interplay withthe Seebeck coefficient in Bi2Se3. As a result, our Bi2Se3 synthesized at 150 sccm gas flow rate exhibited a Seebeck coefficient around −100 μV K–1 and a power factor (PF) of 1.59 × 10–3 W m–1 K–2, which is higher than those of existing thin films and the single-crystal bulk form. This work provides guidance for the controllable preparation of Bi2Se3 thin films with low roughness and high TE performance for potential applications in micro-/nanodevices.

Enhanced Photoresponse and Surface Wettability of Bi2Se3 Film with Annealing at Different Temperatures for Optoelectronic Applications

“…This method offers a means to quantify the total broadening of the material, encapsulating both size effects and microstrain contributions. By integrating these factors, the Williamson−Hall method offers a more nuanced understanding of the structural characteristics of nanomaterials, 30 = + total size strain (4) where β total is the total broadening, β size is the broadening due to the crystallite size, and β strain is the broadening due to strain.…”

“…The optimization of the surface morphology with low surface roughness improves the electrical conductivity of Bi 2 Se 3 with high thermoelectrical performance in nanodevices. 4 The orthorhombic phase of Bi 2 Se 3 is considered to be an n-type semiconductor, and its optoelectronic properties are used in photosensitive devices. On the other hand, a small band gap is found for its rhombohedral phase in the form of a topological insulator.…”

“…Also, the morphological tuning of Bi 2 Se 3 is highly beneficial for solar cell applications. The optimization of the surface morphology with low surface roughness improves the electrical conductivity of Bi 2 Se 3 with high thermoelectrical performance in nanodevices . The orthorhombic phase of Bi 2 Se 3 is considered to be an n-type semiconductor, and its optoelectronic properties are used in photosensitive devices.…”

Enhancement of the thermoelectric performance of Cu3SbSe4 particles by controlling morphology using exfoliated selenium nanosheets

“…[35][36][37] The morphology optimization for thermoelectric materials is an effective method to improve thermoelectric performance. 38,39 Q. Chen et al reported morphology optimization of Bi 2 Se 3 thin film to enhance thermoelectric performance via VSG process. 38 Z. Shi et al reported synthesis plate-like Ca 3 Co 4 O 9 microcrystal particles and its improved thermoelectric performances.…”

“…38,39 Q. Chen et al reported morphology optimization of Bi 2 Se 3 thin film to enhance thermoelectric performance via VSG process. 38 Z. Shi et al reported synthesis plate-like Ca 3 Co 4 O 9 microcrystal particles and its improved thermoelectric performances. 39 In this study, we controlled the morphology of Cu 3 SbSe 4 using exfoliated Se nanosheets.…”