Ecaterina Cristea1, Victor Zalamai2, Eduard Monaico3
Abstract. GaSe nanosheet solutions with controlled dimensions were obtained through exfoliation followed by ultrasonic-assisted fragmentation, using water and acetone as dispersion media. Optical microscopy analysis revealed an efficient size-based separation of GaSe particles via centrifugation. AFM measurements showed that nanosheet sizes range from 50 to 130 nm. The photoluminescence spectrum of a GaSe single crystal exhibits a narrow line at 1.998 eV, characteristic of band-to-band transitions. In GaSe nanosheet solutions, this line shifts to higher energies, reaching 2.05 eV. Additionally, an extra line is observed around 2.4 eV in both solutions. The first transition is attributed to nanosheets of approximately 130 nm, while the 2.4 eV peak is associated with a reduction in nanosheet size to 60 nm.
Keywords: Gallium Selenide, layered semiconductors, exfoliation, photoluminescence
DOI 10.56082/annalsarsciphyschem.2025.1.45
[1]University Lecturer, Department of Telecommunications and Electronic Systems, Faculty of Electronics and Telecommunications, Technical University of Moldova, Chișinău, Republic of Moldova, (ecaterina.cristea@srco.utm.md).
[2]Assoc. Prof., Dr., National Center for Materials Study and Testing, Technical University of Moldova, Chișinău, Republic of Moldova, (victor.zalamai@cnstm.utm.md).
[3]Assoc. Prof., Dr. habilitat, National Center for Materials Study and Testing, Technical University of Moldova, Chișinău, Republic of Moldova, (eduard.monaico@cnstm.utm.md).
PUBLISHED in Annals of the Academy of Romanian Scientists Series on Physics and Chemistry, Volume 10, No1