Synthesis and Characterization of Ga_xIn_1-xSe (0 ≤ x ≤ 1) for Advanced Optoelectronic Applications

Yu Hung Peng^1*, Ching Hwa Ho¹

¹Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan

* Presenter:Yu Hung Peng, email:d11022604@mail.ntust.edu.tw

This research examines Ga_xIn_1-xSe (0 ≤ x ≤ 1) compound growth by liquid phase method and assesses their structural, optical, and electronic properties. XRD and TEM analyses confirm a hexagonal crystal structure with high single-crystalline quality. Raman spectroscopy shows that increasing Ga content shifts vibrational modes to higher wavenumbers. The bandgaps energies range from 1.240 eV to 1.992 eV, with compositions for x ≤ 0.2 exhibiting n-type conductivity, while x ≥ 0.4 displays p-type behavior. An increase in Ga content is correlated with an elevated work function, indicating a shift in the Fermi level. Notably, the p-Ga_0.4In_0.6Se/n-InSe heterojunction device displays excellent rectifying performance with a turn-on voltage of 0.175 V, highlighting its potential for next advanced optoelectronic applications.

Keywords: 2D Ⅲ-Ⅵ semiconductor, Crystal Growth, Direct bandgap, Band Structure, p-n junction devices