* Corresponding author. Tel.: #91-020-5655201; fax: #91-020-5655201. E-mail address: mgt@physics.unipune.ernet.in (M.G. Takwale). Solar Energy Materials & Solar Cells 64 (2000) 333}346 Synthesis of highly conductive boron-doped p-type hydrogenated microcrystalline silicon (c-Si:H) by a hot-wire chemical vapor deposition (HWCVD) technique S.R. Jadkar, Jaydeep V. Sali, M.G. Takwale*, D.V. Musale, S.T. Kshirsagar School of Energy Studies, Department of Physics, University of Pune, Ganeshkhind, Pune 411 007, India Physical and Materials Chemistry Division, NCL, Pashan Raod, Pune 411 007, India Received 15 April 2000 Abstract Boron-doped hydrogenated microcrystalline silicon (c-Si:H) "lms were prepared using hot-wire chemical vapor deposition (HWCVD) technique. Structural, electrical and optical properties of these thin "lms were systematically studied as a function of B  H  gas (diborane) phase ratio (Variation in B  H  gas phase ratio, dopant gas being diluted in hydrogen, a!ected the "lm properties through variation in doping level and hydrogen dilution). Characterization of these "lms from low angle X-ray di!raction and Raman spectroscopy revealed that the high conductive "lm consists of mixed phase of microcrystalline silicon embedded in an amorphous network. Even a small increase in hydrogen dilution showed marked e!ect on "lm microstruc- ture. At the optimized deposition conditions, "lms with high dark conductivity (0.08 ( cm)) with low charge carrier activation energy (0.025 eV) and low optical absorption coe$cient with high optical band gap ( &2.0 eV) were obtained. At these deposition conditions, however, the growth rate was small (6 A s /s) and hydrogen content was large (9 at%).  2000 Elsevier Science B.V. All rights reserved. Keywords: Microcrystalline silicon; Boron doped; HWCVD; Electrical properties; Structural properties; Optical properties 0927-0248/00/$ - see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 7 - 0 2 4 8 ( 0 0 ) 0 0 2 1 9 - 1