Deep ultraviolet picosecond time-resolved photoluminescence studies of AlN epilayers

Nam, K. B.; Li, J.; Nakarmi, M. L.; Lin, J. Y.; Jiang, H. X.
March 2003
Applied Physics Letters;3/17/2003, Vol. 82 Issue 11, p1694
Academic Journal
A1N epilayers with high optical qualities have been obtained by metalorganic chemical vapor deposition on sapphire substrates. Deep UV picosecond time-resolved photoluminescence (PL) spectroscopy has been employed to study the optical transitions in A1N epilayers. Two PL emission lines associated with the donor bound exciton (D[sup 0]X, or I[sub 2]) and free exciton (FX) transitions have been observed, from which the binding energy of the donor bound excitons in A1N epilayers was determined to be around 16 meV. Time-resolved PL measurements revealed that the recombination lifetimes of the I[sub 2] and free exciton transitions in A1N epilayers were around 80 and 50 ps, respectively. The temperature dependencies of the free exciton radiative decay lifetime and emission intensity were investigated, from which a value of about 80 meV for the free exciton binding energy in A1N epilayer was deduced. This value is believed to be the largest free exciton binding energy ever reported in semiconductors, implying excitons in A1N are an extremely robust system that would survive well above room temperature. This together with other well-known physical properties of A1N may considerably expand future prospects for the application of III-nitride materials.


Related Articles

  • Growth of YBa[sub 2]Cu[sub 3]O[sub 7-x] thin films on sapphire with a cerium-oxide sublayer. Gol�dman, E. K.; Plotkin, D. A.; Razumov, S. V.; Tumarkin, A. V. // Technical Physics;Jan99, Vol. 44 Issue 1, p85 

    The possibility is demonstrated of preparing high-quality films of the high-temperature superconductor YBa[sub 2]Cu[sub 3]C[sub 7-d] with thicknesses up to 2.6 �m by dc magnetron sputtering. It is found that inclusions consisting of CuO and YBa[sub 2]Cu[sub 3]O[sub 8] coexist with the...

  • Study of transient photoconductivity of GaN epilayer grown by metalorganic chemical vapor deposition. Chen, Z.Z.; Shen, B.; Zhang, X.Y.; Zhang, R.; Chen, P.; Zhou, Y.G.; Zang, L.; Jiang, R.L.; Huang, Z.C.; Zheng, Y.D.; Wu, Z.S.; Sun, X.T.; Chen, F. // Applied Physics A: Materials Science & Processing;1998, Vol. 67 Issue 5, p567 

    Abstract. The transient photoconductivity (PC) properties of GaN thin film on (0001) sapphire substrate are investigated. The decay curves of PC obtained by YAG:Nd pulsed laser are divided into two special regions, which are the beginning and tail decay regions, corresponding to two time...

  • Epitaxial YBa2Cu3Ox thin films on sapphire with a PrBa2Cu3Ox buffer layer. Gao, J.; Klopman, B. B. G.; Aarnink, W. A. M.; Reitsma, A. E.; Gerritsma, G. J.; Rogalla, H. // Journal of Applied Physics;3/1/1992, Vol. 71 Issue 5, p2333 

    Reports the preparation of epitaxial thin films of YBa[sub2]Cu[sub3]O[subx] on sapphire with a buffer layer of PrBa[sub2]Cu[sub3]O[subx]. Background to the study; Experimental procedures; Results and discussions.

  • Large-area YBa[sub 2]Cu[sub 3]O[sub 7-delta] thin films on sapphire for microwave applications. Cole, B.F.; Liang, G.-C. // Applied Physics Letters;10/5/1992, Vol. 61 Issue 14, p1727 

    Demonstrates the large-area YBa[sub 2]Cu[sub 3]O[sub 7-delta] thin films on sapphire. Utilization of magnesium oxide buffer on M-plane sapphire; Investigation of the film structure using x-ray diffraction; Presence of the low-defect density in the films.

  • Buffer layer/film interactions in the growth of Ti[sub 2]Ba[sub 2]Ca[sub 1]Cu[sub 2]O[sub x].... Bramley, A.P.; Morley, S.M. // Applied Physics Letters;1/23/1995, Vol. 66 Issue 4, p517 

    Investigates the interfacial reactions between Tl[sub 2]Ba[sub 2]Ca[sub1]Cu[sub 2]O[sub x] thin films with CeO[sub 2] buffered sapphire substrates. Deposition of precursor films by rf sputtering; Evidence of significant reaction at the film/buffer layer interface; Dependence of the thickness on...

  • Preparation of Tl2Ba2CaCu2O8 superconducting thin films on sapphire substrates via a two-step chemical deposition process. Collins, B. T.; Ladd, J. A.; Matey, J. R. // Journal of Applied Physics;8/15/1991, Vol. 70 Issue 4, p2458 

    Presents a study which reported the synthesis of single-phase Tl[sub2]Ba[sub2]CaCu[sub2]O[sub8] thin films on 1-cm² single-crystals sapphire substrates (1102) via a two-step chemical deposition process. Details on the resultant films; Monitoring of the structural and chemical composition of...

  • In situ preparation and transport properties of YBa2Cu3O7 films on sapphire with Zr(Y)O2 buffer layers. Adrian, G.; Grabe, G.; Wilkens, W.; Adrian, H.; Huth, M.; Walkenhorst, A. // Journal of Applied Physics;12/1/1991, Vol. 70 Issue 11, p6934 

    Studies preparation and transport properties of thin films on sapphire with buffer layers. Method of the study; Results and discussion; Conclusion.

  • Surface resistance and residual losses of Ag-doped YBa2Cu3O7-δ thin films on sapphire. Pinto, R.; Apte, P. R.; Hegde, M. S.; Kumar, Dhananjay // Journal of Applied Physics;4/15/1995, Vol. 77 Issue 8, p4116 

    Provides information on a study that investigated the surface resistance and residual losses of silver-doped YBa[sub2]Cu[sub3]O[sub7- σ ] thin films on sapphire. Details on the growth and microwave measurements of the thin films; Results and discussion on the study; Conclusion.

  • Oriented growth of ultrathin tungsten films on sapphire substrates. Souk, J. H.; Segmüller, Armin; Angilello, J. // Journal of Applied Physics;7/15/1987, Vol. 62 Issue 2, p509 

    Presents a study that determined the microstructure and orientational relationship of growing tungsten thin films on sapphire substrates. Methodology; Correlation between film thickness and oriented growth; Examination of the strain or stress in the thin films.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics