Abstract
This article investigates hole transport in poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV)/CdSe colloidal quantum dot (CQD) nanocomposites using a modified time-of-flight photoconductivity technique. The measured hole drift mobilities are analyzed in the context of Bässler’s Gaussian disorder model and the correlated disorder model in order to determine the polymer internal morphology of hybrid nanocomposite thin films. This work shows that increasing the CdSe CQD concentration decreases the polymer hole mobility from ~5.9 × 10−6 cm2/Vs in an MEH-PPV film to ~8.1 × 10−8 cm2/Vs in a 20:80 (wt%) MEH-PPV:CdSe CQD nanocomposite film (measured at 25 °C and ~2 × 105 V/cm). The corresponding disorder parameters indicate increasing disruption of interchain interaction with increasing CQD concentration. This work quantifies polymer chain morphology in hybrid nanocomposite thin films and provides useful information regarding the optimal use of semiconductor nanocrystals in conjugated polymer-based optoelectronics.
Highlights
Organic-inorganic hybrid nanocomposites comprising polymers in combination with semiconductor nanocrystals are an important area of research due to the potential to realize optical and electricalCrystals 2012, 2 devices with performance comparable to traditional inorganic semiconductor devices but with less processing complexity and lower manufacturing costs [1]
The measured polymer hole drift mobilities are further analyzed in the context of amorphous film disorder models, Bässler’s Gaussian disorder model (BGDM) [7] and the correlated disorder model (CDM) [8], in order to quantify the polymer internal morphology in the nanocomposites due to the presence of colloidal quantum dot (CQD)
MEH-PPV:CdSe hybrid nanocomposite thin films with different CQD concentrations are investigated using a modified TOF technique enabled by RIR-MAPLE deposition
Summary
Crystals 2012, 2 devices with performance comparable to traditional inorganic semiconductor devices but with less processing complexity and lower manufacturing costs [1]. The measured polymer hole drift mobilities are further analyzed in the context of amorphous film disorder models, Bässler’s Gaussian disorder model (BGDM) [7] and the correlated disorder model (CDM) [8], in order to quantify the polymer internal morphology in the nanocomposites due to the presence of CQDs. An important aspect of this work is that a modified TOF method is demonstrated that is uniquely enabled by the ability to deposit multi-layer films using resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) [9]. The modified TOF photoconductivity method demonstrated in this work resolves these issues by using a two-layer film, wherein the first layer adjacent to the transparent contact consists of MEH-PPV in order to create a thin sheet of photogenerated charge and the second layer consists of the nanocomposite under measurement. The transsit time of the MEH-PPV layer ( pure polymer) is suubtracted fro om the trannsit time of tthe heterosttructure ( heterostructure) to fiind the transsit time of thhe nanocom mposite ( nannocomposite)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
