Temperature-dependent optical properties of B-doped nc-Si:H thin films in the interband region

We report on the thermal effects on optical properties in a B-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin film grown by plasma enhanced chemical vapor deposition, using optical transmission measurements from 10 to 300 K. It is demonstrated that reliable band gaps and optical constants can be deduced by the employment of Forouhi and Bloomer’s dielectric function model [Phys. Rev. B 34, 7018 (1986)] in the interband region, which overcomes the underestimation of the optical band gaps. We have obtained temperature dependence of optical band gaps, absorption coefficient, and refractive index in B-doped nc-Si:H, and discussed the results within the framework of electron-phonon interactions. These optical properties provide an experimental basis for further device design of nc-Si:H.

[1]  Kastner,et al.  Single-electron charging and periodic conductance resonances in GaAs nanostructures. , 1990, Physical review letters.

[2]  P. Cabarrocas,et al.  Optical dispersion relations for crystalline and microcrystalline silicon , 2002 .

[3]  Bloomer,et al.  Optical dispersion relations for amorphous semiconductors and amorphous dielectrics. , 1986, Physical review. B, Condensed matter.

[4]  D. Davazoglou,et al.  Study of the electronic structure of amorphous and crystallized low pressure chemically vapor deposited silicon films near the absorption threshold , 2002 .

[5]  Modified Forouhi and Bloomer dispersion model for the optical constants of amorphous hydrogenated carbon thin films , 1994 .

[6]  N. H. Nickel,et al.  Raman spectroscopy of B-doped microcrystalline silicon films , 2003 .

[7]  A. Pérez‐Rodríguez,et al.  Structural, optical, and electrical properties of nanocrystalline silicon films deposited by hydrogen plasma sputtering , 1998 .

[8]  M. Fujii,et al.  Photoluminescence from B-doped Si nanocrystals , 1998 .

[9]  D. Davazoglou,et al.  Optical properties of SnO2 thin films grown by atmospheric pressure chemical vapour deposition oxiding SnCl4 , 1997 .

[10]  F. C. Marques,et al.  Thermomechanical properties of a-Si:H and a-Ge:H , 2001 .

[11]  Solomon,et al.  Band structure of carbonated amorphous silicon studied by optical, photoelectron, and x-ray spectroscopy. , 1988, Physical review. B, Condensed matter.

[12]  J. Woolley,et al.  Temperature dependence of the energy gap in semiconductors , 1984 .

[13]  R. F. O'Connell,et al.  ELECTRONIC CONDUCTIVITY OF HYDROGENATED NANOCRYSTALLINE SILICON FILMS , 1995 .

[14]  W. Shen,et al.  Study of photocurrent characteristics in PbSrSe thin films for infrared detection , 2002 .

[15]  Daisuke Noguchi,et al.  Residual lattice strain in thin silicon-on-insulator bonded wafers: Effects on electrical properties and raman shifts , 2001 .

[16]  A. Rubino,et al.  Electrical properties of heavily doped μc‐Si:H , 1995 .

[17]  William Paul,et al.  Optical constants of rf sputtered hydrogenated amorphous Si , 1979 .

[18]  Kevin P. Homewood,et al.  Optical absorption study of ion beam synthesized polycrystalline semiconducting FeSi2 , 1995 .

[19]  Ernesto G. Birgin,et al.  Optical constants and thickness determination of very thin amorphous semiconductor films , 2006 .

[20]  Dielectric function of nanocrystalline silicon with few nanometers (<3 nm) grain size , 2003 .

[21]  S. Gupta,et al.  Ex situ spectroscopic ellipsometry and Raman spectroscopy investigations of chemical vapor deposited sulfur incorporated nanocrystalline carbon thin films , 2002 .

[22]  Bloomer,et al.  Optical properties of crystalline semiconductors and dielectrics. , 1988, Physical review. B, Condensed matter.

[23]  S. Ray,et al.  Nanocrystalline silicon as intrinsic layer in thin film solar cells , 1998 .

[24]  Jin Jang,et al.  Microcrystalline silicon thin films studied using spectroscopic ellipsometry , 2002 .

[25]  J. Reverchon,et al.  Photoconductance measurements on thin InGaN layers , 2000 .

[26]  K. O'Donnell,et al.  Temperature dependence of semiconductor band gaps , 1991 .

[27]  K. Wang,et al.  AC electrical properties of nanocrystalline silicon thin films , 2003 .

[28]  F. Koch,et al.  The temperature dependence of the absorption coefficient of porous silicon , 1996 .

[29]  G. Jellison,et al.  Parameterization of the optical functions of amorphous materials in the interband region , 1996 .

[30]  Gerald Earle Jellison,et al.  Optical absorption of silicon between 1.6 and 4.7 eV at elevated temperatures , 1982 .

[31]  Wenzhong Shen,et al.  Effects of high hydrogen dilution on the optical and electrical properties in B-doped nc-Si:H thin films , 2004 .

[32]  Dielectric functions of Si nanocrystals embedded in a SiO 2 matrix , 2003 .

[33]  Gerald Earle Jellison,et al.  The temperature dependence of the refractive index of silicon at elevated temperatures at several laser wavelengths , 1986 .

[34]  Elvira Fortunato,et al.  Highly conductive and highly transparent n-type microcrystalline silicon thin films , 1997 .