Dead zones in colloidal quantum dot photovoltaics: evidence and implications
KAUST Grant NumberKUS-I1-009-21
Permanent link to this recordhttp://hdl.handle.net/10754/597919
MetadataShow full item record
AbstractIn order to fabricate photovoltaic (PV) cells incorporating light-trapping electrodes, flexible foil substrates, or more than one junction, illumination through the top-contact (i.e.: non-substrate) side of a photovoltaic device is desirable. We investigate the relative collection efficiency for illumination through the top vs. bottom of PbS colloidal quantum dot (CQD) PV devices. The external quantum efficiency spectra of FTO/TiO2/PbS CQD/ITO PV devices with various PbS layer thicknesses were measured for illumination through either the top (ITO) or bottom (FTO) contacts. By comparing the relative shapes and intensities of these spectra with those calculated from an estimation of the carrier generation profile and the internal quantum efficiency as a function of distance from the TiO2 interface in the devices, a substantial dead zone, where carrier extraction is dramatically reduced, is identified near the ITO top contact. The implications for device design, and possible means of avoiding the formation of such a dead zone, are discussed.
CitationBarkhouse DAR, Kramer IJ, Wang X, Sargent EH (2010) Dead zones in colloidal quantum dot photovoltaics: evidence and implications. Optics Express 18: A451. Available: http://dx.doi.org/10.1364/OE.18.00A451.
SponsorsThis publication was supported in part by King Abdullah University of Science and Technology (KAUST), Award No. KUS-I1-009-21.
PublisherThe Optical Society