{"title":"Temperature-dependent quantum efficiency analysis of recombination centers in silicon thin-film solar cells","authors":"T. Wagner, U. Rau","doi":"10.1063/1.1566481","DOIUrl":"https://doi.org/10.1063/1.1566481","url":null,"abstract":"We present temperature dependent quantum efficiency (TQE) as a new lifetime spectroscopy (LS) method for the analysis of recombination centers in thin film solar cells. Applying TQE to epitaxial silicon thin-film solar cells grown by ion-assisted deposition at low deposition temperatures T/sub dep/ (450/spl deg/C/spl les/T/sub dep//spl les/650/spl deg/C) unveils that the diffusion length in this material is dominated by Shockley-Read-Hall recombination via two relatively shallow defects with activation energies in ranges of 70-110 and 160-210 meV. At room temperature, the 200-meV defect dominates the material's diffusion length and, in consequence, the photovoltaic device performance. A combination of TQE, deep level transient spectroscopy and minority carrier diffusion length data allows us to deduce an exponential decay of the defect density in the films with increased deposition temperature.","PeriodicalId":108816,"journal":{"name":"3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114720795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Bilyalov, J. Poortmans, R. Sharafutdinov, S. Khmel’, V. Shchukin, O. Semenova, L. Fedina, B. Kolesov
{"title":"Microcrystalline silicon films for solar cells obtained by gas-jet electron-beam PECVD method","authors":"R. Bilyalov, J. Poortmans, R. Sharafutdinov, S. Khmel’, V. Shchukin, O. Semenova, L. Fedina, B. Kolesov","doi":"10.1049/ip-cds:20030665","DOIUrl":"https://doi.org/10.1049/ip-cds:20030665","url":null,"abstract":"The characteristics of thin microcrystalline silicon films obtained by gas-jet electron-beam plasma enhanced chemical vapor deposition (GJ-EB PECVD) method are investigated from the viewpoint of their use for solar cell technology. This method provides a very high deposition rate of 5-10 nm/s in the temperature range of 150-430/spl deg/C. Morphological quality of the films is investigated by means of transmission electron microscopy and Raman spectroscopy. It is shown that a morphological structure of the films consists a mixture of amorphous and microcrystalline fractions. Preliminary electrical characterization of the films is performed using steady-state photoconductivity measurements. The results show a certain potential of GJ-EB PECVD for a solar cell application.","PeriodicalId":108816,"journal":{"name":"3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126410595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Ekins-Daukes, I. Ballard, C. Calder, K. Barnham, T. Trupke, A. Brown, J. Roberts, G. Hill
{"title":"Photovoltaic efficiency enhancement through thermal up-conversion","authors":"N. Ekins-Daukes, I. Ballard, C. Calder, K. Barnham, T. Trupke, A. Brown, J. Roberts, G. Hill","doi":"10.1063/1.1561159","DOIUrl":"https://doi.org/10.1063/1.1561159","url":null,"abstract":"A scheme is presented whereby ambient thermal energy is coupled to sub-band-gap photons through the creation and recombination of electron hole pairs, thereby increasing the short-circuit current and the efficiency of a solar cell. The necessary photon-phonon coupling is demonstrated experimentally, through the observation of anti-Stokes luminescence from QW p-i-n devices. A modest efficiency enhancement is possible for a constrained PV device, but the maximum efficiency does not exceed that of the Shockley-Queisser limit. Only when a temperature difference between the PV device and QW thermal up-convertor is established, can the system exceed the Shockley-Queisser limit.","PeriodicalId":108816,"journal":{"name":"3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134294953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Advanced lifetime spectroscopy: unambiguous determination of the electronic properties of the metastable defect in boron-doped CZ-Si","authors":"Stefan Rein, P. Lichtner, Stefan W. Glunz","doi":"10.1063/1.1544431","DOIUrl":"https://doi.org/10.1063/1.1544431","url":null,"abstract":"By combining data from temperature- and injection-dependent lifetime spectroscopy (TDLS and IDLS) measured by means of the microwave-detected photoconductance decay technique and the quasi-steady state photoconductance technique, respectively, the exact electronic structure of the metastable defect in standard boron-doped Czochralski (Cz) silicon has been determined. A detailed Shockley-Read-Hall analysis of the entire TDLS curve reveals that the Cz-specific defect acts as an attractive Coulomb center (/spl sigma//sub n/(T)=/spl sigma//sub n0/T/sup -2/) which is localized in the upper band gap half at E/sub C/-E/sub t/=0.41 eV and has an electron/hole capture cross section ratio k:=/spl sigma//sub n///spl sigma//sub p/ of 9.3. A new routine for data evaluation allows a transparent SRH analysis of IDLS and TDLS data and enables the accuracy and consistency of the determined defect parameters to be assessed. For the metastable defect in boron-doped Cz-Si perfect agreement between IDLS and TDLS has been found, which demonstrates the excellent performance of lifetime spectroscopy.","PeriodicalId":108816,"journal":{"name":"3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130790304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermal annealing characteristics of amorphous silicon-based solar cells incorporating stable protocrystalline silicon and unstable microcrystalline silicon at the onset of a microcrystalline regime","authors":"J. Ahn, K. H. Jun, M. Konagai, K. Lim","doi":"10.1063/1.1561161","DOIUrl":"https://doi.org/10.1063/1.1561161","url":null,"abstract":"We investigated the light-soaking behaviors and the thermal annealing kinetics of amorphous silicon-based solar cells incorporating hydrogen-diluted films as i-layers deposited at several hydrogen dilution ratios. From the investigation, we confirmed that the protocrystalline silicon was most stable against light soaking, and also that the film deposited at the onset of the microcrystalline regime, which were known to have the most competent device quality and stability, was less stable. Charged dangling bonds defects caused by inhomogeneous microstructure of the onset of the microcrystalline regime, was suggested as one of reasons for the instability at the onset regime.","PeriodicalId":108816,"journal":{"name":"3rd World Conference onPhotovoltaic Energy Conversion, 2003. Proceedings of","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128161587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}