Photovoltaic Properties Of Polymer/Dye Heterojunction Systems

One of the main reasons for the less efficiency of Organic photovoltaic devices is the narrow absorption of the visible spectrum. Therefore, In blends devices with PPV derivatives and fullerenes (or their derivatives), we intend to use dyes to expand its coverage of the visible spectrum, so as to increase the production of excitons and enhance Photovoltaic devices' performance.In this paper, we tried to use different dyes to compound the original devices. By comparing the absorption spectrum of different dyes, finally we selected phthalocyanine dye material. Within polymer / dye co-doped composite film photovoltaic devices and polymer / dye bilayer photovoltaic devices, by trying different doping rates and the thickness of the function film, performance of the devices have been effectively enhanced.Meanwhile, in order to solve the problems which are caused by liquid electrolyte in Dye-sensitized TiO₂ Solar Cells (DSSC), we tried using polymer MEH-PPV or small organic molecules CuPc as the solid electrolyte to form DSSC, which is also called Dye-sensitized Heterojunction Solar Cells (DSH).1) We used TiOPc doping in MEH-PPV photovoltaic devices and MEH-PPV: C60 bulk heterojunction devices with different ratios. TiOPc doping broadend the absorption spectrum of the original devices. Compared with the original devices, MEH-PPV and TiOPc co-doped in ratio 1:2 (wt), the short-circuit current density Jsc and conversion efficiency (?) of the devices, are increased by about 40% and 60%. At the same time Voc also increased. While MEH-PPV:C60 and TiOPc in their best co-doped ratio of 1:5 (wt), Jsc and (?) of the device are increased by about 70% and 90% respectively.2) We evaporated different thickness of copper phthalocyanine (CuPc) in MEH-PPV: PCBM and MEH-PPV:C60 photovoltaic devices. Deposition of a certain thickness of CuPc also expand the coverage of the visible spectrum. Both devices have their best performance when thickness of CuPc are 8nm, compared with the original devices, MEH-PPV: PCBM devices: Jsc and (?) are increased by 80%; MEH-PPV: C60 devices: Jsc and (?) are increased by about 150 % and 175% respectively.3) We used MEH-PPV as a hole transporter in DSH cells, as layer's thickness is 80 nm, device has its optimal performance: Jsc, Voc and (?) are 3.85 mA/cm², 0.96V and 1.34 %. And to CuPc hole transporter layer for the DSH cells, when CuPc is 40 nm: Jsc, Voc and (?) are 248.3μA/cm², 0.61V, 0.058%. Compared with the I₃-/I- liquid electrolyte DSSC cells, DSH cells both have higher Voc.In this paper, there are 31 pieces of map, 10 tables, and 44 reference articles.