Time Resolved Photoluminescence Of Porous Silicon: Evidence For Tunneling Limited Recombination In A Band Of Localized States

Time resolved photoluminescence of porous silicon at room temperature was measured for several emission energies under 2 ns nitrogen laser excitation. For each emission energy studied there is a broad distribution of lifetimes extending over a few decades. The mean value of the distribution varies with the emission energy, from 3 (2.77 eV) to 50 μs (1.96 eV). The results can be explained by assuming a tunneling limited recombination mechanism between bands of localized states. We associate this behavior with a superficial disordered Si:O:H compound rather than with quantum confinement effects.62192381238

The Origin Of Visible Photoluminescence In Low Power A-si1-xcx:h With X > 0.2

Photoluminescence decay measurements were performed in a series of a-Si1-xCx:H samples with 0 < x < 0.5 prepared in the low power regime, i.e. containing virtually no sp2 carbon. The decay is non-exponential and presents two peaks in the lifetime distribution for x > 0.2, one slow peak associated to a-Si:H-like luminescence and a fast peak that is responsible for the temperature independent visible luminescence. We conclude that the efficient temperature independent visible photoluminescence is due to a mechanism that is ineffective in a-Si:H, which we attribute to enhanced Coulomb interaction between electron and hole. © 1999 Elsevier Science Ltd. All rights reserved.1114193197Bullot, J., Schmidt, M.P., (1987) Phys. Status Solidi (b), 143, p. 345Kruangam, D., (1998) Properties of Amorphous Silicon and Its Alloys, p. 337. , T. Searle (Ed.), INSPEC, LondonRobertson, J., (1992) Phil. Mag. B, 66, p. 615Solomon, I., Schmidt, M.P., Tran-Quoc, H., (1988) Phys. Rev. B, 38, p. 9895Pereyra, I., Carreño, M.N.P., Tabacniks, M.H., Prado, R.J., Fantini, M.C.A., (1998) J. Appl. Phys., 84, p. 2371Tessler, L.R., Solomon, I., (1995) Phys. Rev. B, 52, p. 10962Boulitrop, F., Dunstan, D.J., (1983) Phys. Rev. B, 28, p. 5923Dunstan, D.J., Boulitrop, F., (1984) Phys. Rev. B, 30, p. 5945Street, R.A., (1991) Hydrogenated Amorphous Silicon, p. 279. , Cambridge University Press, CambridgeChauvet, O., Zuppiroli, L., Ardonceau, J., Solomon, I., Wang, Y.C., Davis, R.F., (1992) Mat. Sci. Forum, 83-87, p. 1201Sussmann, R.S., Ogden, R., (1981) Phil. Mag. B, 44, p. 137Bässler, H., Gailberger, M., Mahrt, R.F., Oberski, J.M., Weiser, G., (1992) Synth. Met., 49-50, p. 341Su, W.P., Schieffer, J.R., Heeger, A.J., (1979) Phys. Rev. Lett., 44, p. 1698Tessler, L.R., Cirino, L.R., (1996) Amorphous Silicon Technology-1996, MRS Symposium Proceedings-420, p. 783. , PittsburgTsang, C., Street, R.A., (1979) Phys. Rev. B, 19, p. 3027Robertson, J., (1996) Phys. Rev. B, 53, p. 16302Vasil'ev, V.A., Volkov, A.S., Musabekov, E., Terukov, E.I., Chelnokov, V.E., Chernyshov, S.V., Shernyakov, Yu.M., (1990) Sov. Phys. Semicond., 24, p. 445Sibert, W., Carius, R., Fuhs, W., Jahn, K., (1987) Phys. Stat. Sol. (b), 140, p. 311Lormes, W., Hundhausen, M., Ley, L., (1998) J. Non-Cryst Sol., 227-230, p. 57

Erbium Luminescence In A-si:h

We have prepared a-Si:H with erbium impurities by co-sputtering. Efficient photoluminescence at 1.54 μm was observed in as-deposited samples. The maximum luminescence efficiency, 17, was found for an Er/Si concentration ∼ 2 at.% in samples prepared under low cathode bias. These samples have columnar structure and have ∼ 3 at.% O/Si. Annealing under oxygen atmosphere at 300°C can increase 17 at room temperature by a factor 3 and η at 77 K by a factor 5. The optimum erbium concentration is two orders of magnitude larger than in ion implanted crystalline silicon or in glasses. Hydrogen concentration is a fundamental parameter to obtain efficient luminescence. This material is a good candidate for Er3+ based photonic devices. © 1998 Elsevier Science B.V. All rights reserved.227-230PART 1399402Green P.E., Jr., (1996) IEEE J. Selected Areas Commun., 14, p. 764Rare earth doped semiconductors (1994) Mater. Res. Soc. Symp. Proc., p. 316Rare earth doped semiconductors II (1996) Mater. Res. Soc. Symp. Proc., p. 422Polman, A., (1997) J. Appl. Phys., 82, p. 1Priolo, F., Franzò, G., Coffa, S., Polman, A., Libertino, S., Barklie, R., Carey, D., (1995) J. Appl. Phys., 78, p. 3874. , and references thereinShin, J.H., Serna, R., Van Den Hoven, G.N., Polman, A., Van Sark, W.G.J.H.M., Vredenberg, A.M., (1996) Appl. Phys. Lett., 68, p. 997Oestereich, T., Swiatowski, C., Broser, I., (1990) Appl. Phys. Lett., 56, p. 446Bressler, M.S., Gusev, O.B., Kudoyarova, V.Kh., Kuznetsov, A.N., Pak, P.E., Terukov, E.I., Yassievich, I.N., Sturm, A., (1995) Appl. Phys. Lett., 67, p. 3599Zanatta, A.R., Nunes, L.A.O., Tessler, L.R., (1997) Appl. Phys. Lett., 70, p. 511Przybylinska, H., Jantsch, W., Suprun-Belevitch, Y., Stepikhova, M., Palmetshofer, L., Hendorfer, G., Kozanecki, A., Sealy, B.J., (1996) Phys. Rev. B, 54, p. 2532Van Den Hoven, G.N., Shin, J.H., Polman, A., Lombardo, S., Campisano, S.U., (1995) J. Appl. Phys., 78, p. 2642Eaglesham, D.J., Michel, J., Fitzgerald, E.A., Jacobson, D.C., Poate, J.M., Benton, J.L., Polman, A., Kimerlingh, L.C., (1991) Appl. Phys. Lett., 48, p. 2797Miniscalco, W.J., (1991) J. Lightwave Technol., 9, p. 234Street, R.A., (1991) Hydrogenated Amorphous Silicon, , Cambridge Univ. Press, Cambridg

Optimization Of The As-deposited 1.54 μm Photoluminescence Intensity In A-siox : H〈er〉

Erbium-doped a-Si:H has Er3+-related photoluminescence (PL) at ∼1.54 μm (∼0.8 eV). This emission is an intra-4f level transition of the Er3+ ion, which can be increased by adding O. In this paper we present a study of the dependence of the Er3+ luminescence on Er and O concentration ([Er] and [O]) in a-SiOx:H. Samples were prepared by rf-sputtering from a Si target partially covered by small erbium platelets in an Ar + H2 + O2 plasma. The maximum Er3+ luminescence occurs when 10 ≤ [O]/[Er] ≤ 40. Up to 3 O atoms form the Er coordination shell. The extra O increases the excitation of the Er3+ ions. When [O] increases and the density of states at mid-gap becomes larger than [Er], the Er3+ excitation rate decreases. In optimized samples the temperature quenching is less than a factor 2 from 15 to 300 K. The data allow us to conclude that: (a) Efficient room temperature Er3+ PL can be obtained from as-deposited a-SiOx:H(Er). (b) The role of O in a-SiOx:H(Er) is more than just providing non-centrosymmetric environments for Er3+. It also increases the Er3+ excitation rate. © 2000 Elsevier Science B.V. All rights reserved.266-269 A603607Pomrenke, G.S., Klein, P.B., Langer, D.W., (1993) Rare Earth Doped Semiconductors, 301. , Mater. Res. Soc. Symp. Proc., MRS, Pittsburgh, PACoffa, S., Polman, A., Schwartz, R.N., (1996) Rare Earth Doped Semiconductors II, 422. , Mater. Res. Soc. Symp. Proc., MRS, Pittsburgh, PAJudd, B.R., (1962) Phys. Rev., 127, p. 750Michel, J., Ferrante, J.L.B.R.F., Jacobson, D.C., Eaglesham, D.J., Fitzgerald, E.A., Xie, Y.H., Poate, J.M., Kimerling, L.C., (1991) J. Appl. Phys., 70, p. 2672Adler, D.L., Jacobson, D.C., Eaglesham, D.J., Marcus, M.A., Benton, J.L., Poate, J.M., Citrin, P.H., (1992) Appl. Phys. Lett., 61, p. 2181Polman, A., Hoven, G.N.V.D., Custer, J.S., Shin, J.H., Serna, R., Alkemade, P.F.A., (1995) J. Appl. Phys., 77, p. 1256Oesterreich, T., Swialtowski, C., Broser, I., (1990) Appl. Phys. Lett., 56, p. 446Bresler, M.S., Gusev, O.B., Kudoyarova, V.K., Kuznetsov, A.N., Pak, P.E., Terukov, E.I., Yassievich, I.N., Sturm, A., (1995) Appl. Phys. Lett., 67, p. 3599Zanatta, A.R., Nunes, L.A.O., Tessler, L.R., (1997) Appl. Phys. Lett., 70, p. 511Tessler, L.R., Zanatta, A.R., (1998) J. Non-Cryst. Solids, 227-230, p. 399Tessler, L.R., Iñiguez, A.C., (1999) Amorphous and Microcrystalline Silicon Technology - 1998, 507, p. 279. , S. Wagner, M. Hack, H.M. Branz, R. Schroop, I. Shimizu (Eds.), Mater. Res. Soc. Symp. Proc., MRS, Pittsburgh, PAKudoyarova, V.K., Kuznetsov, A.N., Terukov, E.I., Gusev, O.B., Kudryavtsev, Y.A., Ber, B.Y., Gusinskii, G.M., Kuehne, D., (1998) Semiconductors, 32, p. 1234Masterov, V.F., Nasredinov, F.S., Seregin, P.P., Kudoyarova, V.K., Kuznetsov, A.N., Terukov, E.I., (1998) Appl. Phys. Lett., 72, p. 728Piamonteze, C., Iñiguez, A.C., Tessler, L.R., Alves, M.C.M., Tolentino, H., (1998) Phys. Rev. Lett., 81, p. 4652Terrasi, A., Priolo, F., Franz, G., Coffa, S., D'Acapito, F., Mobilio, S., (1999) J. Lumin., 80, p. 363Fuhs, W., Ulber, I., Weiser, G., Bresler, M.S., Gusev, O.B., Kuznetsov, A.N., Kudoyarova, V.K., Yassievich, I.N., (1997) Phys. Rev. B, 56, p. 9545Shin, J.H., Serna, R., Van Der Hoven, G.N., Polman, A., Van Sark, W.G.J., Vredenberg, A.M., (1996) Appl. Phys. Lett., 68, p. 99

Optical Gain In A-sinx:h〈nd〉

We report optical gain measurements in neodymium-doped amorphous hydrogenated silicon sub-nitride (a-SiNx:H〈Nd〉) planar waveguides. Samples (1.5 μm thick) were prepared by reactive rf-sputtering from a silicon target partially covered by metallic neodymium platelets using an Ar + N2 + H2 atmosphere. The substrates are oxidized H〈100〉 silicon wafers that are cleaved to define highly parallel flat waveguide faces. At low temperatures, the photoluminescence spectrum measured at the waveguide edge shows an increased and narrowed peak at 1130 nm when compared with the spectrum taken in the direction of the guide top surface. The guided signal presents supralinear intensity dependence. An optical gain of 270 ± 10 cm-1 was determined using the variable slit method exciting with a CW multiline Ar+ laser at 8 kW/cm2. The photon energy of the Ar+ laser lines is not resonant with any of the Nd3+ transitions, indicating that the excitation is efficiently transferred from the host to the rare earth ions. This result indicates that a-SiNx:H〈Nd〉 can be used as an active optical medium. © 2004 Elsevier B.V. All rights reserved.275769772Pavesi, L., Dal Negro, L., Mazzoleni, C., Franzò, G., Priolo, F., (2000) Nature, 408, p. 440Rare earth doped materials for photonics (2003) Mater. Sci. Eng. B, 105Han, H.S., Seo, S.Y., Shin, J.H., (2001) Appl. Phys. Lett., 79, p. 4568Biggemann, D., Tessler, L.R., (2003) Mat. Sci. and Eng. B, 105, p. 188Weber, M.J., (2001) Handbook of Lasers, , CRC Press Boca RatonHüfner, S., (1978) Optical Spectra in Transparent Rare Earth Compounds, , Academic Press New YorkDieke, G.H., (1968) Spectra and Energy Levels of Rare Earth Ions in Crystals, , Interscience Publishers New YorkShaklee, K.L., Nahaory, R.E., Leheny, R.F., (1973) J. Lumin., 7, p. 284Koechner, W., (1999) Solid State Laser Engineering, , Fifth Ed. Springer Berli

Near Infra-red Photoluminescence Of Nd3+ In Hydrogenated Amorphous Silicon Sub-nitrides A-sinx:h〈nd〉

Neodymium-doped hydrogenated amorphous silicon sub-nitrides a-SiN x:H〈Nd〉 thin films were deposited by rf-sputtering using a Si target partially covered by metallic Nd chips and Ar + N2 + H 2 sputtering gas. Characteristic Nd3+ near infra-red (NIR) photoluminescence (PL) was detected between 10 and 300 K with peaks at ∼935, ∼1090 and ∼1390 nm, corresponding to the intra-4f transitions 4F3/2 → 4I9/2, 4F3/2 → 4I11/2 and 4F3/2 → 4I13/2, respectively. Measurements using different excitation wavelengths indicate that the Nd 3+ excitation occurs through the a-SiNx:H matrix. Varying the nitrogen content x from 0 to nearly 1.3 increases the matrix bandgap. The PL efficiency is maximum when the bandgap corresponds to twice the 4F3/2→4I9/2 transition, indicating a defect-related energy transfer mechanism. The temperature quenching can be as low as less than a factor 3 between 10 and 300 K for 2.8 eV gap samples. Thermal annealing can enhance the PL intensity by a factor 10. Neodymium concentrations above ∼3 × 1020 atoms/cm 3 slightly reduce the PL intensity probably due to excess of inactive defect centers. Along with erbium-doped amorphous silicon alloys, a-SiNx:H〈Nd〉 can be used in the development of photonic devices in the future. © 2003 Published by Elsevier B.V.10501/03/15188191Pavesi, L., Dal Negro, L., Mazzoleni, C., Franzò, G., Priolo, F., (2000) Nature, 408, p. 440Canham, L., (2000) Nature, 408, p. 411Tessler, L.R., (1999) Braz. J. Phys., 29, p. 616Weber, M.J., (2001) Handbook of Lasers, , CRC Press, Boca Raton, FLGan, R., Liu, F., Qi, L., Wang, J., (1997) Mater. Lett., 32, p. 91Castilho, J.H., Marques, F.C., Barberis, G.E., Rettori, C., Alvarez, F., Chambouleyron, I., (1989) Phys. Rev. B, 39, p. 2860Tessler, L.R., Iñiguez, A.C., (1999) Proceedings of the Materials Research Society Symposium, 507, p. 279. , S. Wagner, M. Hack, H.M. Branz, R. SchroopI, I. Shimizu (Eds.), MRS, Pittsburgh, PAAustin, I.G., Jackson, W.A., Searle, T.M., Bhat, P.K., Gibson, R.A., (1985) Phil. Mag. B, 52, p. 271Fuhs, W., Ulber, I., Weiser, G., Bresler, M.S., Gusev, O.B., Kusnetsov, A.N., Kudoyarova, V.K., Yassievich, I.N., (1997) Phys. Rev. B, 56, p. 9545Street, R.A., (1991) Hydrogenated Amorphous Silicon, , Cambridge University Press, CambridgeTessler, L.R., Iñiguez, A.C., (2000) J. Non Cryst. Solids, 266-269, p. 603Takahei, K., Taguchi, A., Nakagome, H., Uwai, K., Whitney, P.S., (1989) J. Appl. Phys., 66, p. 494

Time-resolved Photoluminescence In A-sinx:h〈nd〉planar Waveguides: Evidence For Stimulated Emission

We performed lifetime measurements on the 1128 nmNd3+ emission from a neodymium-doped amorphous hydrogenated silicon sub-nitride (a SiN x:H〈Nd〉) planar waveguide. The 1.5 μm thick sample was prepared by reactive rf-sputtering. Lifetime measurements were performed exciting with a multiline Ar+ laser. The sample temperature was varied between 25 and 300 K, and the excitation power between 0.2 and 8 kW/cm2. In all measurement conditions the luminescence decay can be expressed by two exponentials. The fast decay has a lifetime between 40 and 60 μs and the slow decay has a lifetime between 1 and 3 ms. The excitation photon energy is not resonant with any of the Nd3+ transitions, consequently the excitation energy must be transferred from the host nitride to the Nd3+ ions. The fast lifetime is almost independent of the temperature, indicating that it is related to the excitation transfer process. As the temperature increases the probability of carrier recombination through processes that do not excite Nd3+ ions increases. The slow lifetime is associated with the intrinsic Nd3+ lifetime. It is shorter at low temperatures and high excitation rates. At 26 K, it decreases by a factor 2 when the excitation power goes from 2 to 8 kW/cm2. The lifetime decrease with the excitation power is associated with the onset of stimulated emission from the Nd3+ ions. © 2004 Elsevier B.V. All rights reserved.275773775(2003) Mater. Sci. Eng. B, 105Weber, M.J., (2001) Handbook of Lasers, , CRC Press Boca RatonHüfner, S., (1978) Optical Spectra in Transparent Rare Earth Compounds, , Academic Press New YorkDieke, G.H., (1968) Spectra and Energy Levels of Rare Earth Ions in Crystals, , Interscience Publishers New YorkBiggemann, D., Tessler, L.R., (2003) Mat. Sci. and Eng. B, 105, p. 188Tessler, L.R., Biggeman, D., (2005) Optical Materials, , these ProceedingsTessler, L.R., Biggemann, D., (2003) Mater. Sci. Eng. B, 105, p. 165Van Den Hoven, G.N., Shin, J.H., Polman, A., Lombardo, S., Campisano, S.U., (1995) J. Appl. Phys., 78, p. 2642Bresler, M.S., Gusev, O.B., Terukov, E.I., Yassievich, I.N., Zacharchenya, B.P., Emel'Yanov, V.I., Kamenev, B.V., Timoshenko, V.Yu., (2001) Mater. Sci. Eng. B, 81, p. 5

Temperature Independent Er3+ Photoluminescence Lifetime In A-si:h<er> And A-siox:h<er>

The photoluminescence (PL) lifetime of Er3+ in a-Si:H<Er> and a-SiOx:H<Er> was measured between 15 and 300K in a set of samples containing ∼1 at.% Er and up to ∼10 at.% O. The room temperature PL intensity increased and the temperature quenching decreased with O content. The maximum PL intensity at 15K, however, is obtained from samples with no intentional oxygen added. The PL lifetimes were obtained using the quadrature frequency resolved spectroscopy (QFRS) technique. The QFRS signal was well fitted supposing two lifetimes, the fast decay in the 20-150μs range and the slow decay in the 200-830μs range, consistently increasing with the O content of the samples. For all samples both the fast and the slow lifetimes did not depend on the temperature within experimental incertitude. Our results are interpreted supposing two different lattice sites for Er 3+ in the hosts. Moreover, the de-excitation of the Er3+ ions by multiple phonon emission is negligible in this class of materials. © 2003 Published by Elsiver B.V.10501/03/15165168(2001) Mater. Sci. Eng. B, 81Tessler, L.R., (1999) Braz. J. Phys., 29, p. 616Bressler, M.S., Gusev, O.B., Kudoyarova, V.Kh., Kuznetsov, A.N., Pak, P.E., Terukov, E.I., Yassievich, I.N., Sturm, A., (1995) Appl. Phys. Lett., 67, p. 3599Fuhs, W., Ulber, I., Weiser, G., Bresler, M.S., Gusev, O.B., Kusnetsov, A.N., Kudoyarova, V.K., Yassievich, I.N., (1997) Phys. Rev. B, 56, p. 9545Kuhne, H., Weiser, G., Terukov, E.I., Kusnetsov, A.N., Kudoyarova, V.K., (1999) J. Appl. Phys., 86, p. 896Bresler, M.S., Gusev, O.B., Sobolev, N.A., Terukov, E.I., Yassievich, I.N., Zakharchenya, B.P., Gregorkevich, T., (1999) Phys. Sol. State, 41, p. 770Tessler, L.R., Iñiguez, A.C., (1998) Mater. Res. Soc. Symp. Proc., MRS, 507, p. 279. , S. Wagner, M. Hack, H.M. Branz, R. Schroop, I. Shimizu (Eds.), Amorphous and Microcrystalline Silicon Technology, Pittsburgh, PADepinna, S.P., Dunstan, D.J., (1984) Phil. Mag. B, 50, p. 579Tessler, L.R., Iñiguez, A.C., (1998) Mat. Res. Soc. Proc., 507, pp. 505-517. , S. Wagner, M. Hack, H.M. Branz, R. Schroop, I. Shimizu (Eds.), Amorphous and Microcrystalline Silicon Technology, PittsburghKamenev, B.V., Timoshenko, V.Y., Konstantinova, E.A., Kudoyarova, V.K., Terukov, E.I., Kashkarov, P.K., (2002) J. Non-cryst. Sol., 299, p. 668Van Den Hoven, G.N., Shin, J.H., Polman, A., Lombardo, S., Campisano, S.U., (1995) J. Appl. Phys., 78, p. 2642Piamonteze, C., Iñiguez, A.C., Tessler, L.R., Martins, M.C., Tolentino, H., (1998) Phys. Rev. Lett., 81, p. 4652Terukov, E.I., Undalov, Yu.K., Kudoyarova, V.Kh., Koughia, K.V., Kleider, J.P., Gueunier, M.E., Meaudre, R., (2002) J. Non-cryst. Sol., 299-302, p. 699Shin, J.H., Serna, R., Van Den Hoven, G.N., Polman, A., Van Sark, W.G.J.H.M., Vredenberg, A.M., (1996) Appl. Phys. Lett., 68, p. 997Street, R.A., (1991) Hydrogenated Amorphous Silicon, , Cambridge University Press, Cambridg

Optoelectronic Properties Of Highly Conductive Microcrystalline Sic Produced By Laser Crystallisation Of Amorphous Sic

The optoelectronic properties of undoped and doped microcrystalline silicon carbide thin films, prepared by excimer (ArF) laser crystallisation of plasma enhanced chemical vapour deposited hydrogenated amorphous silicon carbide, are analysed. All films show more than six orders of magnitude increase relative to the conductivities before the laser crystallisation. It is shown that the increase in conductivity is not predominantly due to the activation of dopant atoms. However, dopant sites, but not carbon content (up to 30 at%), play an important role in electrical transport in μc-SiC. We also report the observation of blue photoluminescence at room temperature from the undoped laser irradiated samples having a carbon content of 35 at%. The spectrum exhibits two visible peaks (1.8 eV and 2.6 eV), while the as-deposited films show only the 1.8 eV peak.198-200PART 2907910Matsumoto, Y., Hirata, G., Takakura, H., Okamoto, H., Hamakawa, Y., (1990) J. Appl. Phys., 67, p. 6538Kruangam, D., Toyama, T., Hattori, Y., Deguchi, M., Okamoto, H., Hamakawa, Y., (1987) J. Non-cryst. Solids, 97-98, p. 293Futagi, T., Matsumoto, T., Katsuno, M., Onta, Y., Mimura, H., Kitamura, K., (1993) Mater. Res. Soc. Proc., 283, p. 389Demichelis, F., Pirri, C.F., Tresso, E., (1992) J. Appl. Phys., 72, p. 1327Lau, S.P., Marshall, J.M., Dyer, T.E., Hepburn, A.R., Davies, J.F., (1993) J. Non-cryst. Solids, 164-166, p. 813Lau, S.P., Marshall, J.M., Dyer, T.E., Hepburn, A.R., Davies, J.F., (1994) Mater. Res. Soc. Symp. Proc., 339, p. 647Lau, S.P., Marshall, J.M., Dyer, T.E., (1995) Phil. Mag. B, , in pressFogarassy, E., Pattyn, H., Elliq, M., Slaoui, A., Prevot, B., Stuck, R., De Unamuno, S., Mathe, E.L., (1993) Appl. Surf. Sci., 69, p. 231El-Kader, E.M.A., Oswald, J., Kocka, J., Chab, V., (1994) Appl. Phys. Lett., 64, p. 2555Matsumoto, T., Takahashi, J., Tamaki, T., Futagi, T., Mimura, H., Kanemitsu, Y., (1994) Appl. Phys. Lett., 42, p. 226Lau, S.P., (1995), Ph.D. thesis, University of Wales Swanse

Photoluminescence Of Er-doped Silicon Nanoparticles From Sputtered Sio X Thin Films

We present a study of the Er3+ photoluminescence from Er-doped thin SiOx films prepared by reactive RF sputtering from a silicon target partially covered by metallic erbium platelets in an Ar + O2 atmosphere. Annealing at 1250 °C induces the formation of silicon nanocrystals and modifies the Er3+ luminescence spectrum due to changes in the Er3+ environment. The photoluminescence efficiency decreases by two orders of magnitude with nanoparticle formation. This decrease may be due to less efficient energy transfer processes from the nanocrystals than from the amorphous matrix, to the formation of more centro-symmetric Er3+ sites at the nanocrystal surfaces or to very different optimal erbium concentrations between amorphous and crystallized samples. © 2005 Elsevier B.V. All rights reserved.2806/07/15842845Pacifici, D., Franzò, G., Priolo, F., Iacona, F., Dal Negro, L., (2003) Phys. Rev. B, 67, p. 245301Kenyon, A.J., Chryssou, C.E., Pitt, C.W., Shimizu-Iwayama, T., Hole, D.E., Sharma, N., Humphreys, C.J., (2002) J. Appl. Phys., 91, p. 367Kik, P.G., Brongersma, M.L., Polman, A., (2000) Appl. Phys. Lett., 76, p. 2325Makimura, T., Kondo, K., Uematsu, H., Li, C., Murakami, K., (2003) Appl. Phys. Lett., 83, p. 5422Franzò, G., Boninelli, S., Pacifici, D., Priolo, F., Iaconna, F., Bongiorno, C., (2003) Appl. Phys. Lett., 82, p. 3871Chen, C.Y., Chen, W.D., Song, S.F., Xu, Z.J., Liao, X.B., Li, G.H., Ding, K., (2003) J. Appl. Phys., 94, p. 5599D. Mustafa, L.R. Tessler, unpublishedTessler, L.R., Iñiguez, A.C., (2000) J. Non-Cryst. Solids, 266-269, p. 603Tessler, L.R., Piamonteze, C., Martins Alves, M.C., Tolentino, H., (2000) J. Non-cryst. Solids, 266-269, p. 59