Mechanical properties of micro-structured porous silicon film （PS） were studied combining X-ray diffraction with micro-Raman spectroscopy. The micro-structured porous silicon samples with different porosities rangin...Mechanical properties of micro-structured porous silicon film （PS） were studied combining X-ray diffraction with micro-Raman spectroscopy. The micro-structured porous silicon samples with different porosities ranging from 30.7700 to 96.2500 were obtained by chemical etching. Lattice parameters of the samples were measured using X-ray diffraction and its maximal change is up to （1.000.） This lattice mismatch with the bulk silicon substrate may introduce residual stress to the porous film. The residual stress measurement by micro-Raman spectroscopy reveals that the maximum of tensile residual stress has reached GPa level in the porous film. Moreover, the lattice mismatch and its corresponding residual stress are increasing with the porosity of PS, but average （elastic） modulus is about 14.5 GPa, one order of magnitude lower than that of substrate Si. The mechanical properties of PS have a close relation with its micro-pore structure.展开更多
Silicon thin films with different crystalline ratio(Xc) have been deposited by varying silane content(SC) of reactive gases in the RF-PECVD process.The effects of silane content on performance of the materials and the...Silicon thin films with different crystalline ratio(Xc) have been deposited by varying silane content(SC) of reactive gases in the RF-PECVD process.The effects of silane content on performance of the materials and the relationship between microstructure and opto-electronic properties were studied by means of Raman measurements,photoconductivity(σ_ ph ),and dark conductivity(σ_d),followed by the measurements of light absorption coefficient(α),the product of quantum efficiency,mobility and lifetime (ημτ),before,during and after light soaking,respectively.The results indicate that the microcrystalline silicon near the transition region is suitable to prepare microcrystalline silicon of device grade,and that the amorphous region of the material is responsible to the light induced degradation.展开更多
Hydrogenated microcrystalline silicon （μc-Si：H） intrinsic films and solar cells are prepared by plasma enhanced chemical vapor deposition （PECVD） with various hydrogen dilution ratios. The influence of hydrogen ...Hydrogenated microcrystalline silicon （μc-Si：H） intrinsic films and solar cells are prepared by plasma enhanced chemical vapor deposition （PECVD） with various hydrogen dilution ratios. The influence of hydrogen dilution ratios on electrical characteristics is investigated to study the phase transition from amorphous to microcrystalline silicon. During the deposition process,the optical emission spectroscopy （OES） from plasma is recorded and compared with the Raman spectra of the films,by which the microstructure evolution of different 1-12 dilution ratios and its influence on the performance of μc-Si： H n-i-p solar cells is investigated.展开更多
文摘Mechanical properties of micro-structured porous silicon film （PS） were studied combining X-ray diffraction with micro-Raman spectroscopy. The micro-structured porous silicon samples with different porosities ranging from 30.7700 to 96.2500 were obtained by chemical etching. Lattice parameters of the samples were measured using X-ray diffraction and its maximal change is up to （1.000.） This lattice mismatch with the bulk silicon substrate may introduce residual stress to the porous film. The residual stress measurement by micro-Raman spectroscopy reveals that the maximum of tensile residual stress has reached GPa level in the porous film. Moreover, the lattice mismatch and its corresponding residual stress are increasing with the porosity of PS, but average （elastic） modulus is about 14.5 GPa, one order of magnitude lower than that of substrate Si. The mechanical properties of PS have a close relation with its micro-pore structure.
基金This workis supported by the State Key Development Programfor Basic Research of China ( Grant No. G2000028202 ,G2000028203)the Key Project of Education Bureau (Grant No.02167)the State Key Development Program(2002303261)
文摘Silicon thin films with different crystalline ratio(Xc) have been deposited by varying silane content(SC) of reactive gases in the RF-PECVD process.The effects of silane content on performance of the materials and the relationship between microstructure and opto-electronic properties were studied by means of Raman measurements,photoconductivity(σ_ ph ),and dark conductivity(σ_d),followed by the measurements of light absorption coefficient(α),the product of quantum efficiency,mobility and lifetime (ημτ),before,during and after light soaking,respectively.The results indicate that the microcrystalline silicon near the transition region is suitable to prepare microcrystalline silicon of device grade,and that the amorphous region of the material is responsible to the light induced degradation.
基金the State Key Development Program for Basic Research of China(Nos.2006CB202602,2006CB202603)Tianjin Assistant Foundation for the National Basic Research Program of China(No.07QTPTJC29500)~~
文摘Hydrogenated microcrystalline silicon （μc-Si：H） intrinsic films and solar cells are prepared by plasma enhanced chemical vapor deposition （PECVD） with various hydrogen dilution ratios. The influence of hydrogen dilution ratios on electrical characteristics is investigated to study the phase transition from amorphous to microcrystalline silicon. During the deposition process,the optical emission spectroscopy （OES） from plasma is recorded and compared with the Raman spectra of the films,by which the microstructure evolution of different 1-12 dilution ratios and its influence on the performance of μc-Si： H n-i-p solar cells is investigated.
