N. Murugesan, R. Padhan, S. Yang, S.A. Kadam, A.V. Sumant, R. Divan, D. Rossenmann, N.R. Pradhan
Jackson State University,
United States
Keywords: transition metal dichalcogenide (TMD), infrared (IR), photo transistors (PTs)
Summary:
Two-dimensional (2D) materials have garnered significant attention for their unique electronic, optical, and mechanical properties, making them prime candidates for next-generation electronic and optoelectronic devices. Among these, Tungsten diselenide (WSe2), a p-type semiconducting transition metal dichalcogenide (TMD), has shown great promise for infrared (IR) photodetection due to its direct bandgap of 1.6 eV in single atomic layer and a strong light-matter interaction. [1] However, the practical implementation of TMDs material-based photo transistors (PTs) faces persistent challenges at IR range due to the band edge absorption. Most of these materials photosensitivity limited to the UV and visible range. To explore the possibility of these materials photodetection application in IR or far IR range, we extended a heterostructure geometry of PT using WSe2 a visible absorbing material stacked with an extremely low band gap (~ 0.2eV) IR absorbing material PdSe2 to enhance the photoresponsivity. PdSe2 can absorb the IR photons and transferred to the WSe2 layers where the photo generated carriers can be trapped at the interface of PdSe2 and WSe2 by applied gate voltage to tune the carrier transport. The synergistic interaction between the bandgap properties of PdSe2 and WSe2 in this device highlights a promising pathway for developing high-performance IR-sensitive devices.