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Using quantum dot photoluminescence for load detection

: Moebius, M.; Martin, J.; Hartwig, M.; Baumann, R.R.; Otto, T.; Gessner, T.


AIP Advances 6 (2016), Nr.8, Art. 085309, 7 S.
ISSN: 2158-3226
Fraunhofer ENAS ()

We propose a novel concept for an integrable and flexible sensor capable to visualize mechanical impacts on lightweight structures by quenching the photoluminescence (PL) of CdSe quantum dots. Considering the requirements such as visibility, storage time and high optical contrast of PL quenching with low power consumption, we have investigated a symmetrical and an asymmetrical layer stack consisting of semiconductor organic N,N,N′,N′-Tetrakis(3-methylphenyl)-3,3′-dimethylbenzidine (HMTPD) and CdSe quantum dots with elongated CdS shell. Time-resolved series of PL spectra from layer stacks with applied voltages of different polarity and simultaneous observation of power consumption have shown that a variety of mechanisms such as photo-induced charge separation and charge injection, cause PL quenching. However, mechanisms such as screening of external field as well as Auger-assisted charge ejection is working contrary to that.