Crystalline SiGe films grown on Si substrates using laser-assisted plasma-enhanced chemical vapor deposition at low temperature

Abstract

Compared with conventional plasma-enhanced chemical vapor deposition, laser-assisted plasma-enhanced chemical vapor deposition ͑LAPECVD͒ can be used to deposit crystalline SiGe films on Si substrates at low temperature. In the LAPECVD system, a CO 2 laser with a wavelength of 10.6 m was utilized to assist the pyrolytical decomposition of SiH 4 and GeH 4 reactant gases. The resultant Si 0.78 Ge 0.22 films were obtained and verified through the use of the Auger electron spectroscopy measurement. As the diffraction pattern of a glancing incident angle X-ray diffraction measurement had indicated, several significant diffraction peaks corresponding to a diamond-cubic structure at ͑111͒, ͑220͒, and ͑311͒ were clearly observed. Crystalline SiGe films were also identified by the electron diffraction pattern of high-resolution transmission electron microscopy images.

Carrier drift velocity balance mechanism in Si-based thin film solar cells using graded microcrystalline SiGe absorption layer

“…Using a glancing incident angle X-ray diffraction (GI-XRD) system and a high-resolution transmission electron microscopy (HR-TEM), the observed X-ray diffraction patterns and selective area electron diffraction patterns revealed the microcrystalline structure of the various deposited films (Lee et al, 2007(Lee et al, , 2009Lee and Tsai, 2013). Using the Hall measurement at room temperature, the hole concentration and the hole mobility of the p-Si films measured were 3.58 ± 0.13 Â 10 18 cm À3 and 0.43 ± 0.02 cm 2 /V s, while the electron concentration and the electron mobility of the n-Si films were obtained as 1.50 ± 0.06 Â 10 19 cm À3 and 3.66 ± 0.09 cm 2 /V s, respectively.…”

“…Since the tunable band gap of the lc-SiGe films by varying the Ge content, a graded lc-SiGe film is thus realized to modify the energy band structure of the i-absorption layer. According to the previous reports (Lee et al, 2007(Lee et al, , 2009Lee and Tsai, 2013), the high quality microcrystalline Si and microcrystalline SiGe films could be deposited using the laserassisted plasma-enhanced chemical vapor deposition (LAPECVD) system. In this work, the p-type lc-Si, undoped lc-SiGe, and n-type lc-Si films used for the p-i-n Si-based thin film solar cells are deposited using the LAPECVD system.…”

Stress Evolution during Ge Nanoparticles Growth in a SiO2 Matrix

“…The as-deposited (ad) sample and the sample annealed at 500 °C show two broad maxima at 2θ = ∼26° and ∼50°, which correspond to the amorphous Ge structure. − Annealing at 550 °C led to crystallization of the Ge nps, as evidenced by the appearance of diffraction lines at 26°, 46°, and 53°, corresponding to the hkl = 111, 220, and 311 crystallographic directions of the crystalline Ge structure, respectively. The QDs remained crystalline up to an annealing temperature of 650 °C.…”

Performance Improvement of Microcrystalline p-SiC/i-Si/n-Si Thin Film Solar Cells by Using Laser-Assisted Plasma Enhanced Chemical Vapor Deposition

“…In contrast, the c-Si films did not have this problem and were more suitable to be applied to construct the thin film solar cells. In this work, the laser-assisted plasma enhanced chemical vapor deposition (LAPECVD) system invented by our research group was used to directly deposit c-Si films without further annealing treatment [4][5][6][7][8]. The silane (SiH 4 ) reacting gas could be easily and efficiently decomposed into Si atoms under the combined action of the plasma and CO 2 laser, due to the high absorption coefficient of SiH 4 reacting gas at a wavelength of CO 2 laser (10.6 m).…”