Advancing photodetection capabilities via Pb-induced modifications in SnSe crystals

Ternary compounds of PbxSn1−xSe with varying values of x (0, 0.05, 0.1) were synthesized through the direct vapor transport method to investigate the influence of Pb incorporation on the properties of SnSe. The as-grown compounds are subjected to elemental composition and purity analysis using EDX. Field emission scanning electron microscopy reveals morphological characteristics of crystal exteriors. Powder X-ray diffraction highlights that both the unaltered and Pb-incorporated samples exhibit the orthorhombic lattice structure of SnSe. Through Raman spectroscopy, the characteristic vibrational mode of SnSe is identified, and with increasing Pb content, the corresponding peak shift is observed. X-ray photoelectron spectroscopy is employed to validate both the binding states and chemical composition of the synthesized SnSe and Pb-doped SnSe single crystals. The optical band gap was determined using UV–Vis–NIR spectroscopy. In the application part optoelectronic properties of all the samples, encompassing their responsive behavior, have been systematically investigated. Furthermore, key factors influencing photodetection attributes are evaluated, encompassing parameters such as photocurrent, rise time, decay time, photoresponsivity (R), and specific detectivity (D).