Hybrid nanocrystal/polymer solar cells based on tetrapod-shaped CdSexTe1-x nanocrystals

A series of ternary tetrapodal nanocrystals of CdSexTe1-x with x = 0 ( CdTe), 0.23, 0.53, 0.78, 1 ( CdSe) were synthesized and used to fabricate hybrid nanocrystal/ polymer solar cells. Herein, the nanocrystals acted as electron acceptors, and poly( 2-methoxy-5-( 2'-ethyl-hexyloxy)-1,4-phenylene vinylene) ( MEH-PPV) was used as an electron donor. It was found that the open circuit voltage ( V-OC), short-circuit current ( J(SC)) and power conversion efficiency (eta) of the devices all increased with increasing Se content in the CdSexTe1-x nanocrystals under identical experimental conditions. The solar cell based on the blend of tetrapodal CdSe nanocrystals and MEH-PPV ( 9: 1 w/w) showed the highest power conversion efficiency of 1.13% under AM 1.5, 80 mW cm(-2), and the maximum incident photon to converted current efficiency ( IPCE) of the device reached 47% at 510 nm. The influence of nanocrystal composition on the photovoltaic properties of the hybrid solar cells was explained by the difference of the band level positions between MEH-PPV and the nanocrystals.