Photoelectric Characterstics Of Amorfhous InGaAs Detector Material

Amorphous materials and crystalline materials have common character,but they have some differences. The structure character of amorphous materials are long-range disorder and short-range order comperared. Semiconductors are still lack of systematic and detailed study. In this paper, our study on amorphous(a-) In_xGa_1-xAs films includes the preparation, characterization, and hydrogen passivation.We deposited a-InGaAs flims by molecular-beam epitaxy and RF magnetron sputtering. We have characterized structure and surface morphology of amorphous films by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) . And we calculate the radical distribution function and pair correlation function from XRD in order to obtain microstructure data of amorphous In_xGa_1-xAs thin films. On basis of programming in matlab, we have fitteda curve of optical constants and have analyzed the influence of working pressure on the optical constants.In addition, We have deposited a-GaAs:H films. We investigated the influence of doping hydrogen on the structure, surface morphology, and photoelectrical properties. We found the passivation of hydrogen on the amorphous films. Hydrogen induces decreasing state density and blue shifts in absorption edge.