Materials Optimization for Silicon Heterojunction Solar Cells Using Spectroscopic Ellipsometry

摘要: Our research team has used hot wire chemical vapor deposition (HWCVD) to fabricate silicon heterojunction (SHJ) solar cells on p-type FZ substrates with efficiencies as high 18.2%. The best are deposited anisotropically-textured (100) where an etching process creates pyramidal facets (111) crystal faces. Texturing increases J sc through enhanced light trapping, yet our highest V oc devices un-textured substrates. One of the key factors in maximizing efficiency SHJ is optimization material properties 3 - 5 nm thick hydrogenated amorphous (a-Si:H) layers create junction and back contact these cells. Such technically challenging because difficulty measuring extremely thin layers. This compounded by fact that such substrate- thickness-dependent. In this study, we have utilized spectroscopic ellipsometry (SE) photoconductivity decay conclude a-Si:H films grown substantially similar addition, analysis substrate temperature dependence surface roughness evolution reveals a substrate-independent mechanism smoothening activation energy 0.28 eV. Analysis passivation 0.63