Synthesis And Research On The Properties Of Organic Photovoltaic Materials Based On Ullazine

With the rapid development of the world economy, the human demand for energy is increasing. The traditional fossil energy sources are limited and non-renewable, so researchers have devoted themselves to seeking for sustainable use of energy sources, such as solar energy, wind energy, hydroenergy and geothermal energy. Among them, solar energy on account of its unique advantages, such as clean without pollution, abundant reserves, no regional restrictions, renewable etc, have drawn much attention. Besides, solar cells are currently one of the ways of effectively utilizing solar energy. At present, solar cells based on inorganic silicon have achieved commercial application. However, high costs and serious environmental pollution limits its further development and application. Meanwhile, organic photovoltaic(OPV) materials have attracted extensive attention and made gratifying progress because of its low cost, light weight, easy-to-made large-area flexible devices, etc. The PCE of the polymer solar cells has exceeded 10%, and the PCE of the dye sensitized solar cells has reached 13%. Obviously, this is far short of the purpose of commercial application. Therefore, it requires that the researchers devote unremitting efforts to developing new materials. Based on this, this article designed and synthesized polymer solar cells and dye sensitized solar cells, and the photovoltaic performances, thermal properties and electrochemical properties of these materials were investigated systematically.1. We have designed and synthesized two novel side-chain polymers QP1 and QP2, by introducing the ullazine side chain for the first time, to extend the conjugation length and increase solubility. After the synthesis of copolymers QP1, we found that its absorption spectra spectrum was rather narrow. Therefore, we synthesized the random conjugated terpolymer QP2 with the additional DPP unit to broaden the spectrum. As a result, the Jsc of QP1 and QP2 are 3.34 and 5.58 m A cm-2 respectively, in line with the broader absorption spectra of QP2, the higher hole mobility of QP2 than QP1. The Voc of QP1 and QP2 are0.39 and 0.58 V respectively, in consistent with the higher HOMO energy level.Therefor, the PCE of QP1 and QP2 are unideal, with 0.46% and 1.34%, respectively.2. We have designed and synthesized there dyes QD1, QD2 and QD3 based on ullazine unit as electron donors. Thereinto, the anchoring group of QD1, namely electron acceptor, was cynoacrylic acid. In QD2 and QD3, we chose a weak acceptor carboxylic acid as anchoring groups, QD2 with double band, a thiophene spacer and QD3 with double band, a benzene spacer as π-conjugating spacers respectively. The absorption spectra of QD2 and QD3 have blue shifted with respect to QD1. Their short-circuit photocurrent density(Jsc) are 12.28,3.82 and 2.98 m A cm-2, their open circuit voltage(Voc) are 0.65, 0.60 and 0.53 V, their power conversion efficiency are 5.28%,1.30% and 1.05%, respectively.