Light-induced enhancement of quantum dot photovolt

Light-induced enhancement of quantum dot photovoltaic devices with nitrogen doped titanium oxide capping layers
Jialin Yu, Jilin Xia, Inho Kim, Benjamin L. French,
Hanna M. Haverinen, T.L. Alford, Ghassan E. Jabbour (2013)

For the first time it is reported that nitrogen-doped titanium oxide with light annealing can improve the device performance by 300% when acting as an interfacial layer between CdSe quantum dot/poly-3-hexylthiophene and the cathode in the photovoltaic devices. Substitutional N doping with a concentration of 1.2 at.% was found by X-ray photoelectron spectroscopy which was responsible for 0.1 eV band gap reduction of TiOx. Photoluminescence and the external quantum efficiency spectrum confirmed the enhanced charge collection and association rate after light annealing. Three-dimensional atomic force microscopy results agreed with the series resistance measurements, confirming that a good contact was achieved. The topography study also indicated that the active layer morphology changed upon light annealing. Improved stability and longer lifetime were also found with TiOxNy capped devices, which were optimized with light annealing. TiOx capped devices were also evaluated for comparison in this study.
http://www.sciencedirect.com/science/article/...9913004230


Cover image - ScienceDirect
www.sciencedirect.com/science/journal/15661199/14

ScienceDirect
Original Research Article; Pages 3339-3347; Jialin Yu, Jilin Xia, Inho Kim, Benjamin L. French, Hanna M. Haverinen, T.L. Alford, Ghassan E. Jabbour. Abstract ...
https://www.google.com/?gws_rd=ssl#q=Hanna+M....E.+Jabbour

......set for release in Dec 2014


.....info on this link may provide a clue as to why
https://www.google.com/?gws_rd=ssl#q=nitrogen...solar+2014


Light-soaking-free inverted polymer solar cell (i-PSC) devices are demonstrated by incorporating nitrogen doped sol–gel titanium sub-oxide (N-TiOx). A heavily doped electron transport layer in i-PSCs, N-TiOx on indium tin oxide yields an Ohmic contact with the bulk heterojunction layer that does not exhibit light-soaking processes. This results in highly efficient i-PSCs with power conversion efficiencies of 8.8%.
http://onlinelibrary.wiley.com/doi/10.1002/ae...8/abstract


.....light starting to show through the seams, so no I don't mind waiting to see where QMC shines 1st