Impact of structural and optical properties tunability of SnSe2 thin films on its optoelectronic properties

Abstract

As a result of the precise controllability of the properties of tin diselenide and the possibility of harmonious integration with silicon technology in many applications. Attention was focused on tin diselenide and the effect of many variables during or after growth on its properties, especially the optoelectronic and photovoltaic. Consequently, a systematic study is represented on the substrate temperature influence (27–200) °C on the crystal structure, morphology, optical and electrical properties of the deposited films. Depending on the results obtained from the XRD, FE-SEM, spectrophotometric, and DC conductivity measurements, the elevation of substrate temperature up to 100 °C achieved the highest crystallite and grain size which has been accompanied by the lowest energy gap and highest conductivity. Furthermore, the dispersion behavior is analyzed and interpreted with detailed calculations for the dielectric and electronic parameters. Next, under the same conditions of the substrate temperatures, isotype (Bi2Te3/SnSe2) and anisotype (Sb2Te3/SnSe2) heterojunctions are fabricated. Their microelectronic parameters are estimated, yielding an ideal Schottky behavior and lower barrier height (0.67 eV) for Sb2Te3/SnSe2 at the optimum temperature. The conduction mechanism is interpreted in detail using the proposed band diagram. Moreover, the effect of power density variation on the two categorized devices is investigated, giving rise to a bias-dependent photodetection behavior of the isotype heterojunction and a significant self-powered photodetection behavior for the anisotype heterojunction. The anisotype detector records R, D*, LDR, and SNR of about 299 mA/W, 1.71 × 1011 Jones, 69.89 dB, and 3121.4, respectively. Ultimately, the photovoltaic characteristics of the anisotype heterojunction have been evaluated in detail, yielding a promising performance of Voc, Jsc, FF, and PCE of about 0.547 volts, 29.9 mA/cm2, 38.09, and 6.23%, respectively.