Marianna L Kemell

Dr. Marianna L Kemell

Department of Chemistry, University of Helsinki, Helsinki, Finland
orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 March 2005 in Critical Reviews in Solid State and Materials Sciences
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Journal Article
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Marianna L KemellMarianna L Kemell
Marianna L Kemell
Mikko RitalaMikko Ritala
Mikko Ritala
MLMarkku Leskelä
Markku Leskelä
CuInSe2 and its alloys with Ga and/or S are among the most promising absorber materials for thin film solar cells. CuInSe2-based solar cells have shown long-term stability and the highest conversion efficiencies of all thin film solar cells, above 19%. Solar cells based on these materials are also very stable, thus allowing long operational lifetimes. The preparation of a thin film solar cell is a multistage process where every step affects the resulting cell performance and the production cost. CuInSe2 and other Cu chalcopyrites can be prepared by a variety of methods, ranging from physical vapor deposition methods such as evaporation and sputtering to low-temperature liquid phase methods such as electrodeposition. The present review discusses first the concept and operation principle of thin film solar cells, as well as the most important thin film solar cell materials. Next, the properties of CuInSe2 and related compounds, as well as features of solar cells made thereof are reviewed. The last part of the text deals with deposition methods used for the preparation of CuInSe2 and Cu(In,Ga)Se2 thin film absorbers and solar cells. Although the emphasis here is on absorber preparation methods, buffer and conducting oxide preparation are discussed as well.

6 December 2010 in Advanced Functional Materials
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Journal Article
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MKMarjo Kettunen
Marjo Kettunen
RSRiitta J. Silvennoinen
Riitta J. Silvennoinen
NHNikolay Houbenov
Nikolay Houbenov
ANAntti Nykänen
Antti Nykänen
Janne RuokolainenJanne Ruokolainen
Janne Ruokolainen
OIOlli Ikkala
Olli Ikkala

24 September 2005 in Journal of the American Chemical Society
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Journal Article
Closed access
Marianna L KemellMarianna L Kemell
Marianna L Kemell
VPViljami Pore
Viljami Pore
Mikko RitalaMikko Ritala
Mikko Ritala
MLMarkku Leskelä
Markku Leskelä
MLMika Lindén
Mika Lindén

5 September 2016 in Biotechnology for Biofuels
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Journal Article
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JKJaana Kuuskeri
Jaana Kuuskeri
MHMari Häkkinen
Mari Häkkinen
PLPia Laine
Pia Laine
OSOlli-Pekka Smolander
Olli-Pekka Smolander
FTFitsum Tamene
Fitsum Tamene
TLTaina Lundell
Taina Lundell
The white-rot Agaricomycetes species Phlebia radiata is an efficient wood-decaying fungus degrading all wood components, including cellulose, hemicellulose, and lignin. We cultivated P. radiata in solid state cultures on spruce wood, and extended the experiment to 6 weeks to gain more knowledge on the time-scale dynamics of protein expression upon growth and wood decay. Total proteome and transcriptome of P. radiata were analyzed by peptide LC–MS/MS and RNA sequencing at specific time points to study the enzymatic machinery on the fungus’ natural growth substrate. According to proteomics analyses, several CAZy oxidoreductase class-II peroxidases with glyoxal and alcohol oxidases were the most abundant proteins produced on wood together with enzymes important for cellulose utilization, such as GH7 and GH6 cellobiohydrolases. Transcriptome additionally displayed expression of multiple AA9 lytic polysaccharide monooxygenases indicative of oxidative cleavage of wood carbohydrate polymers. Large differences were observed for individual protein quantities at specific time points, with a tendency of enhanced production of specific peroxidases on the first 2 weeks of growth on wood. Among the 10 class-II peroxidases, new MnP1-long, characterized MnP2-long and LiP3 were produced in high protein abundances, while LiP2 and LiP1 were upregulated at highest level as transcripts on wood together with the oxidases and one acetyl xylan esterase, implying their necessity as primary enzymes to function against coniferous wood lignin to gain carbohydrate accessibility and fungal growth. Majority of the CAZy encoding transcripts upregulated on spruce wood represented activities against plant cell wall and were identified in the proteome, comprising main activities of white-rot decay. Our data indicate significant changes in carbohydrate-active enzyme expression during the six-week surveillance of P. radiata growing on wood. Response to wood substrate is seen already during the first weeks. The immediate oxidative enzyme action on lignin and wood cell walls is supported by detected lignin substructure sidechain cleavages, release of phenolic units, and visual changes in xylem cell wall ultrastructure. This study contributes to increasing knowledge on fungal genetics and lignocellulose bioconversion pathways, allowing us to head for systems biology, development of biofuel production, and industrial applications on plant biomass utilizing wood-decay fungi.

12 December 2006 in Advanced Materials
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Journal Article
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RRR. H. A. Ras
R. H. A. Ras
Marianna L KemellMarianna L Kemell
Marianna L Kemell
JWJ. de Wit
J. de Wit
Mikko RitalaMikko Ritala
Mikko Ritala
GBG. Ten Brinke
G. Ten Brinke
OIO. Ikkala
O. Ikkala

10 May 2011 in Chemistry of Materials
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Journal Article
Closed access
MKMaarit Kariniemi
Maarit Kariniemi
JNJaakko Niinistö
Jaakko Niinistö
THTimo Hatanpää
Timo Hatanpää
Marianna L KemellMarianna L Kemell
Marianna L Kemell
Timo SajavaaraTimo Sajavaara
Timo Sajavaara
MLMarkku Leskelä
Markku Leskelä