Physics and CompSci Research
Street Broad Scientific
likely to gain electrons than EDOT. In terms of the band gap, poly-EDST has a higher band gap than PEDOT. The band gap is defined as the difference between the frontier orbitals of the molecules[10]. It provides insight into the conductivity of the molecule through the conclusion that the lower the band gap is, the greater the conductivity of the molecule. Like EDOT, it can be mixed with other molecules to have more favorable qualities. When EDST is mixed with EDOT, the new mixture, EDOT-EDST, has a lower band gap than PEDOT and poly-EDST. Like mentioned before, this lower band gap shows that EDOTEDST is more conductive than PEDOT and poly-EDST. In terms of functionality, EDOT-EDST is a better conductive polymer than PEDOT, but it is still overshadowed by PEDOT:PSS.
Figure 5. 3D Structure of VDOT as Seen When Built in WebMO ProDOT (3,4-Propylenedioxythiophene), visualized in Figure 6, is primarily used as an auxiliary electrode in solar panels[12]. These electrodes can have multiple roles. In a two electrode system, the auxiliary electrode serves as the cathode or the anode depending on the charge of the working electrode. Three electrode systems have superseded the two electrode system. In these modern systems, the auxiliary electrode has to balance the amount of electricity going to the working electrode. The polymer, PProDOT, can also be used for displays as it is a stable electrochromic polymer[13]. These types of polymers change and contrast colors when charges are applied. PProDOT is able to change between different shades of blue, according to its charge.
Figure 4. 3D Structure of EDST as Seen When Built in WebMO The next disubstituted derivative of thiophene examined in this study is VDOT (3,4-Vinylenedioxythiophene), and it can be seen in Figure 5. VDOT is composed of the same amount of carbon, oxygen, and sulfur as EDOT. However, the ethylene bridge is replaced with a vinylene bridge as noted in the name of the molecule. Because of this replacement, the band gap of VDOT decreases to a point that is lower than the band gap of EDOT just slightly[11]. Because of the lower band gap and the increased stability, VDOT was considered to be the replacement for EDOT, but PEDOT:PSS soon came after the development of VDOT. Since then, VDOT has been greatly overshadowed by the mixture of PEDOT:PSS.
Figure 6. 3D Structure of ProDOT as Seen When Built in WebMO Volume 3 | 2013-2014 | 73