Temperature dependence of band gaps in sputtered SnSe thin films

The Department of Electrical and Electronics Engineering covers communications, signal processing, high voltage, electrical machines, power distribution systems, radar and electronic warfare, RF, electromagnetic and photonics topics. Most of the theoretical courses in our department are supported by qualified laboratory facilities. Our department has been accredited by MÜDEK since 2013. Within the scope of joint training (COOP), in-company training opportunities are offered to our students. 9 different companies train our students for one semester within the scope of joint education and provide them with work experience. The number of students participating in joint education (COOP) is increasing every year. Our students successfully completed the joint education program that started in the 2019-2020 academic year and started work after graduation. Our department, which provides pre-graduation opportunities to its students with Erasmus, joint education (COOP) and undergraduate research projects, has made an agreement with Upper Austria University of Applied Sciences (Austria) starting from this year and offers its students undergraduate (Atılım University) and master's (Upper Austria) degrees with 3+2 education program. Our department, which has the only European Remote Radio Laboratory in Foundation Universities, has a pioneering position in research (publication, project, patent).

Organizational Unit

Department of Electrical & Electronics Engineering

Department of Electrical and Electronics Engineering (EE) offers solid graduate education and research program. Our Department is known for its student-centered and practice-oriented education. We are devoted to provide an exceptional educational experience to our students and prepare them for the highest personal and professional accomplishments. The advanced teaching and research laboratories are designed to educate the future workforce and meet the challenges of current technologies. The faculty's research activities are high voltage, electrical machinery, power systems, signal and image processing and photonics. Our students have exciting opportunities to participate in our department's research projects as well as in various activities sponsored by TUBİTAK, and other professional societies. European Remote Radio Laboratory project, which provides internet-access to our laboratories, has been accomplished under the leadership of our department with contributions from several European institutions.

Abstract

Temperature-dependent transmission experiments were performed for tin selenide (SnSe) thin films deposited by rf magnetron sputtering method in between 10 and 300 K and in the wavelength region of 400-1000 nm. Transmission spectra exhibited sharp decrease near the absorption edge around 900 nm. The transmittance spectra were analyzed using Tauc relation and first derivative spectroscopy techniques to get band gap energy of the SnSe thin films. Both of the applied methods resulted in existence of two band gaps with energies around 1.34 and 1.56 eV. The origin of these band gaps was investigated and it was assigned to the splitting of valence band into two bands due to spin-orbit interaction. Alteration of these band gap values due to varying sample temperature of the thin films were also explored in the study. It was seen that the gap energy values increased almost linearly with decreasing temperature as expected according to theoretical knowledge.

Description

Terlemezoglu, Makbule/0000-0001-7912-0176; Gasanly, Nizami/0000-0002-3199-6686; Delice, Serdar/0000-0001-5409-6528; parlak, mehmet/0000-0001-9542-5121; Gasanly, Nizami/0000-0002-3199-6686; SURUCU, Özge/0000-0002-8478-1267; Gullu, Hasan Huseyin/0000-0001-8541-5309