Surface Morphology And Photoluminescence Properties Of A-GaAs:Se Detector

Abstract: (GaAs:Se) films with thickness 0.5 μm have been prepared by flash evaporation technique on glass substrate under vacuum of 10-5mbar. These films have been annealed at different temperatures ( 373 , 473)K. The surface morphological characteristics by atomic force microscope (AFM). The roughness was decrease with increasing annealing temperature for amorphous film but start upward when the films crystallized. The grain size increases with increasing annealing temperature upto temperatures (373,473) K . The spectral response of GaAs:Se was studied. The values of responsively, specific detectivity and quantum efficiency increases with increases annealing temperature but NEP decreases with increases annealing temperature. The Photoluminescence peak of a-GaAs:Se films located at 832.215, 829.87 and 827.538 for temperature at RT,100 and 200 oC which corresponding to an energy gap 1.49 , 1.494 and 1.498 eV respectively. This may be associated which that the electron in bottom of conduction band recombines with hole in the valance band.

REFERENCES

[1] S. Kayali, J. Ponchak and R. Shaw "GaAs MMIC Reliability Assurance Guide Line for Space Applications" NASA 1996. http/www.Google.com.

[2] R.K. Willardson and Albert C. Beer "Semiconductor and Semimetal" vol 2, Academic press ,inc. London LTD 1975

[3] J.C.Knights,in: "the physics of hydrogenated amorphous silicon",ed.J.D.Joannopulos and G.Lucovsky,Topics in Applied physics, Vol.55(springr,Berlin,1981)p.5

[4] W.Paul and D.A. Anderson,solar Energy Mater .5 (1981)229.

[5] J.C.Knights and R.A.Lujan,appl.phys.Lett.35(1979)244

[6] R.Messier and R.C.Ross,J,Appl.phys.53 (1982)6220

[7] L.Alimoussa,H.Carchano .A.Fassi-Fihri,F. Lalande and R.Loussier,J.PhysC1-(1982) 341

[8] A.Gheorghiu,T.Rappenau,s,Fisson and M.L they, thin solid films 120 (1984)491

[9] R.Murri,f.Gozzo,N.pinto ,L.Schiavulli,c,DeBlasi and D.Manno,J.Non-cryst.solids 127(1991)12.

[10] C.R Absernathy, F. Ren, P.W. Wisk, S.J. Pearton, R Esagui,Appl. Phys. Lett. 61 (1992) 109

[11] L.J. Guido, G.S. Jackson, D.C. Hall, W.E. Plano, N. Hollonayak,J.Appl Phys. Lett. 52 (1988) 522.

[12] J.A. Silberman, T.J. de LyonJ.M. Woodall, Appl. Phys. Lett. 58(1991) 2126.

[13] D. Olego, M. Cardona, Phys. Rev. B. 22 (1980) 886.