Vesna Jović

Quantum efficiency and responsivity of InSb photodiodes utilizing the Moss-Burstein effect

Abstract In this work a detailed analysis of the quantum efficiency of InSb n+-p photodetectors produced by liquid phase epitaxy is given, in the case when the n+ region is doped to such a level that the Moss-Burstein effect plays an important role. Our starting point was the theoretically determined coefficient of intrinsic absorption and derived expressions for the generated photocurrent in the n+ region, depletion layer and p-phase of the photodetector. The results are presented in the form of graphical dependence of the quantum efficiency on the wavelength, with the electron concentration in the n+ layer as a parameter.

Synergetic effect of additives on the hardness and adhesion of thin electrodeposited copper films

Thin copper films were electrodeposited on a polycrystalline coldrolled copper substrate. The composition of the laboratory-made copper sulphate electrolyte was changed by the addition of various additives. The influence of chloride ion (Cl), polyethylene glycol (PEG) and 3-mercapto-1-propane sulfonic acid (MPSA) on mechanical and adhesion properties of the electrodeposited copper films was investigated using Vickers microindentation technique. Calculations of the film hardness and adhesion were carried out using composite hardness models of Korsunsky and Chen-Gao. The hardness of the composite system is influenced by the adhesion of the copper film to the substrate. Increasing adhesion corresponds to increasing values of the calculated adhesion parameter b, named the critical reduced depth. When additives are added to a plating solution, the copper deposition mechanism is changed and fine-grained microstructure without the formation of microscopic nodules is obtained.