Investigating the performance of N-type janus 2D WSSe monolayer photo-detectors by enhancing its optoelectronic properties

Abstract

Photo-detector based on the (P, Mn, As)-doped janus WSSe monolayer is the area of interest in this work. Internal (IQE), External (EQE) and total quantum efficiency (ηQE) are analyzed as figure of merit of the WSSe ML based photo-detector. The quantum efficiencies are dependent on the absorption coefficient of the 2D material. In our work, properties such as optical and electronic of janus WSSe pristine and n-doped–(P, Mn, As) WSSe are discussed in depth. The optical properties include the study of absorption coefficient (α), dielectric function(real (Ɛ1), imaginary (Ɛ2)). Next, the formation and binding energy of both the system i.e. pristine and doped have been calculated and is found to be stable. Further total density of state (TDOS) and band structure is extracted which are the part of electronic properties. Moreover, the asymmetricity in the TDOS behavior is due to the presence of n-type doping impurities in the WSSe ML. TDOS calculation concludes the introduction of magnetic attributes in the n-doped system which was absent in the pristine system. Also, the band gaps of the pristine and n-doped systems are in close agreement to the TDOS behavior. On the other side the reduce band gap of the n-doped system marks the presence of the defect states in the lower region of the conduction band. Lastly, the device parameters namely, IQE, EQE and ηQE of WSSe ML photodetectors are reported with higher values for Mn-doped WSSe ML separately.