Ag/n–Si/p–MgSe/(Ag, C, Au, Pt) devices designed as current rectifiers, photodetectors and as ac signal filters suitable for VLC, IR and 6G technologies

Abstract

Abstract Herein the fabrication and practical applications of p − MgSe thin films as active p − layer of electronic devices are reported. MgSe films are prepared by a vacuum evaporation technique onto n − Si substrates under a vacuum pressure of 10–5 mbar. The films are morphologically, structurally, electrically and opto-electronically investigated. Having identified the work function of p − MgSe as 6.74 eV, the role of Ag, C, Au and Pt metal contacts on the performance of the n − Si/ p − MgSe (SM) diodes are studied. It is observed that high rectification ratios of ∼104 and 102 are achieved at an applied voltage of 3.0 V for the Ag/SM/C and Ag/SM/Ag diode structures, respectively. In addition, a current responsivity to visible and infrared light of ∼0.70 A W−1 is observed for the Ag/SM/Ag channels. The noise equivalent ratios, the external quantum efficiency and the detectivity of the Ag/SM/Ag diodes suit requirements of visible light and infrared communication detectors. Moreover, studies of the capacitance-voltage characteristics showed capacitor characteristics. The depleting of the Ag/SM/Ag capacitors is possible up to 50 MHz. Furthermore, analyzing the capacitance, resistance and cutoff frequency spectra have shown that the Ag/SM/Ag device channels can perform as negative resistance sources with cutoff frequency values that suits 6G technology requirements.