Electrical and photoelectrical properties of MoN/n-Si surface-barrier structures

Abstract

Subject and purpose. The subject of research is the electrical and photoelectric properties of the МoN/n-Si heterostructure fabricated for the first time by means of the deposition of thin film of molybdenum nitride (n-type conductivity) by the reactive magnetron sputtering onto single crystal substrates of n-type Si. The purpose of the work is to fabricate the photosensitive MoN/n-Si surface-barrier structures, determine the barrier parameters and dominant mechanisms of current transfer through the obtained heterostructure at direct and reverse biases, investigate the photoelectric properties and causes of losses of photogenerated charge carriers in the obtained heterostructures. Method and methodology. Direct and reverse volt-ampere characteristics of the MoN/n-Si heterostructure were measured at various temperatures, as well as when irradiated with white light with an intensity of Popt= 80 mW/cm2 and three lasers with λ = 405, 646, 780 nm with intensity Iopt = 5 mW cm-2. Results. The obtained heterojunctions with the height of potential barrier φ0 = eVbi = 0.37 еV have pronounced rectifying properties. The dominant current transport mechanisms through the heterojunction under investigation were determined: at forward bias, volt-ampere characteristics are well described within the generation-recombination and tunneling-recombination models with the participation of surface states, and аt reverse bias, they are described within the tunnel model. Conclusion. It was established that when illuminated with white light with the intensity of Popt = 80 mW/cm2, the reverse current Ilight increases compared with its value in the dark Idark by more than an order of magnitude due to the separation of photogenerated electron-hole pairs. The photosensitivity of this heterostructure to monochromatic illumination by lasers with electromagnetic wavelengths λ = 405, 646, 780 nm and intensity Iopt = 5 mW cm-2 is shown. The results obtained allow us to c

Keywords

• current transport mechanisms
• heterojunction
• molybdenum nitride
• recombination
• silicon