Photosensor of CDSSE for Fiber Optics Applications

Peter Shindov(a), Nasko Elektronov(b),Valery Serbezov(c), Franz Herbst(c)
a: Technical College-"John Atanasoff"
b: JN-Corp.
c: Multicoats Ltd.

Abstract

The development of new generations of laser source for fiber optic’s applications require more fast new photosensors with spectral characteristics in visible range. The idea of this work is development of technology and device – fast photosensor with spectral range adapted to modern lasers for the quickly increasing needs of optoelectronics and fiber optics communications. By pulsed laser deposition (PLD) usage UV N2 Laser for ablation λ=337.1 nm, energy per pulse 8 mJ and CW 60 W CO2 Laser for heating are produced thin CdSxSe1-x films on quartz substrate. Polycrystalline thin films with thickness from 0.5 to 2.0 μm and dominant orientation – (002) are formed by energy density 4.5 J/cm2 and repetition rate 20 Hz .The thin films are investigated by EDAX and SEM. The films are additional thermo treatment for increasing ratio photocurrent – dark current. This ratio reaches 107. By means of TEA UV N2 Laser with energy per pulse-0.3 mJ, pulse duration 2 ns are formed planar Ohm contacts from CdO directly onto thin film. The contacts are investigated by XRD. By means of coordinate table the contacts are formed on the backside of the structure. The dimension of photosensitive structure is 250x250 μm. The distance between contacts areas is 10 μm. The spectral response of devices is measured. The maximum spectral sensitive is at λ=575 nm. Lux ampere characteristics are measured. The increasable fronts and decreаsаble fronts at the structure are measured. They are 2 ns, at ratio 1000.