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