The innovation engine for new materials

Melissa Dangler

Melissa Dangler, Metallurgical and Materials Engineering, Colorado School of Mines


Metallurgical and Materials Engineering


Colorado School of Mines


Kelly Peterson

Faculty Sponsor(s): 

Michael Chabinyc

Faculty Sponsor's Department(s): 


Project Title: 

Doping of the Organic Semiconductor P3HT with a Lewis Acid Reaction

Project Description: 

Interest in low-cost, solution processable organic electronics has grown in recent years due to the increased demand for flexible, lightweight, thin, and energy efficient devices. In order to create these devices, doping is necessary to increase the natural conductivity of semiconducting polymers. The conjugated polymer poly(3-hexylthiophene-2,5-diyl) (P3HT), has long been established as such an organic semiconductor. On its own, the strong Lewis acid tris(pentafluorophenyl)borane (BCF) has been shown to successfully act as a p-type dopant of P3HT. However, BCF, when used in conjunction with 1,4-benzoquinone (BQ), has been shown to oxidize decamethylferrocene and it is likely to do the same to P3HT, leaving it positively charged. In this study, BCF was mixed in varying ratios with BQ in order to dope the P3HT. The focus of this work is to determine whether the addition of BQ to dopant mixtures effectively increases the doping efficiency of BCF. Changes in electronic and chemical structure associated with the doping of P3HT were studied using FTIR and UV-Vis spectroscopy techniques. Conductivity tests were then performed on thin film samples using a 4-point probe analysis. From the initial UV-Vis results, mixtures with ratios of BQ to BCF that are greater than 1:2 effectively dope P3HT. Such dopant combinations may offer a new avenue for increasing the performance of future P3HT-based organic electronic devices.